The Roman Empire was founded in 27 BCE. It was the first Roman emperor, Augustus, who was responsible for the establishment of the empire after defeating Marc Antony at the Battle of Actium in 31 BCE. This brought an end to the Roman Republic which had existed for 482 years, from 509 to 27 BCE. The Roman Empire would continue to expand for the next two centuries; experiencing incredible wealth whilst facing very few military defeats. Eventually the empire became unstable facing constant civil war, barbarian invasion and financial ruin. The Empire would fall in 476 CE when the city of Rome was sacked by the Goths.

The Roman emperor had absolute authority in matters of war, social reforms and religious matters. He would often delegate responsibilities to the senate as well as rely on them for advice. When the Roman Empire was at its largest, in 117 CE, it stretched from the English/Scottish border to Saudi Arabia, an area of almost 2 million square miles. The population of the empire at its height was 70 million, around 20% of the entire world. The Roman Empire had an incredible impact on the world shaping its legal, philosophical, religious and architectural values.

GIF of Roman Territories Roman Territories GIF

Page Contents


Fall of the Republic (82 to 27 BCE)

During the first century BCE there was filled with constant civil war and unrest. Beginning with Sulla and Marius through to Octavian (Augustus) and Marc Antony. It was when Octavian won a decisive battle against Marc Antony that this period of strife in Rome came to an end. Following Octavian bringing an end to the senate ruled republic and starting the emperor controlled empire a two-hundred year peace followed. Something which had never been seen in classical antiquity before.

Battle of Actium - 31 BCE Battle of Actium (31 BCE)

First Few Centuries (27 BCE to 235 CE)

The first centuries of the Roman Empire were ones of constant Roman expansion. Under Trajan in 117 CE, Roman territories included Italy, Northern Africa, Egypt, Mesopotamia, Turkey, Southern Europe, France, Spain and England/Wales. The economy of Rome was incredibly strong due to its military victories.

It was 69 CE that the empire first faced instability in the years of the empire. It is known as the year of the four emperors. After the emperor Nero had been disposed of in 68 CE, Galba ceased control, however, he was the first of four emperors to be placed their through military means. The chaotic year was brought to an end when Vespasian marched on Rome deposing of the previous emperor Vitellius. Vespasian founded the Flavian dynasty that would last for twenty-seven years.

Circus Maximus Sketch Circus Maximus

The era of the five good emperors followed (96 to 180 CE); with Nerva, Trajan, Hadrian, Antoninus Pius and Marcus Aurelius. Under these emperors stability was established, prosperity was returned and the empire was expanded and consolidated.

Crisis of the Third Century (235 to 284 CE)

By 235 CE the empire would be engulfed in the crisis of third century. Over a period of fifty years barbarian conquests, civil war, disease and a major recession would bring the empire to breaking point. When the emperor Severus Alexander was assassinated in 235 CE it lead to a five year period in which over twenty people would stake their claim to the throne. It would be Diocletian who would essentially save the Roman Empire when he became emperor in 284 CE. He introduced the tetrarchy and split the empire into two in order to make it more manageable along with many other reforms which stabilised the Roman Empire.

Decline of the Roman Empire (284 to 476 CE)

Despite Diocletian making major reforms to the Roman Empire he could not prevent it from its inevitable fate. Growing incursions from barbarian tribes, increasing economic problems, change in core values and an ineffective army all contributed to the Rome’s decline and fall in 476 CE when the Goths led by Odovacar sacked the city and brought an end to the Western Roman Empire.

Sack of Rome Sack of Rome

Founding the Empire (31 to 27 BCE)

Following Octavian’s victory over Marc Antony it would traditionally be expected for Octavian to disband his legions and give control of the Roman state back to the senate. However, the Roman Republic had been in a state of constant civil was for the past sixty years. Octavian argued that he could not submit control of the state in case others attempted to take control by force.

Additionally, Augustus had the loyalty of the majority of the legions as well as having a vast personal wealth. This combination put Octavian in an incredibly strong position. To further strengthen his power, Octavian dismantled the legions who were not loyal to his cause reducing the amount of legions throughout the Roman state from fifty to twenty-eight. Ensuring that no one had the means to challenge him.

In 27 BCE, Octavian was given the name of Augustus and the title of ‘princeps’ which means the first citizen. Augustus was also granted the following powers:

  • Ability to veto any of the senate’s decisions
  • Title of 'Princeps Senatus' (most important senate member)
  • Authority to call senate meeting
  • Authority over grain supply
  • Authority to maintain his own legions
  • Authority to take control of any province if he believes it necessary
  • Ten year governorship of Hispania, Gaul, Syria and Egypt

Augustus used his power to introduce major social reforms as well as initiating many large building programmes across Rome. He introduced laws to punish adultery, discourage divorce and encourage larger families. He also looked to stimulate cultural progression and was patron to both Virgil and Horace. Outside of Rome Augustus looked to expand Rome’s territories in order to protect it from barbarian hordes. He expanded the Roman Empire to include everything south of the Danube and everything west of the Elbe.

Temple of Mars Ultor Temple of Mars Ultor

Augustus succeeded in bringing an end to a period of more than a half century of civil war and conflict in Rome. His reign established the ‘Pax Romana’, an unprecedented period of peace in classical antiquity which lasted longer than two-hundred years. On his deathbed in 14 CE, forty-one years after he had taken control, his famous last words were "Behold, I found Rome of clay, and leave her to you of marble". Augustus founded the Julio-Claudian dynasty which would continue to rule Rome until the death of Nero in 68 CE.

Mausoleum of Augustus Mausoleum of Augustus

Early Empire (27 BCE to 96 CE)

Julio-Claudian Dynasty (27 BCE to 68 CE)

The Julio-Claudian dynasty consisted of the first five Roman emperors: Augustus, Tiberius, Caligula, Claudius and Nero. None of Augustus’ successors would outdo his achievements; Tiberius and Claudius were by far the most successful members out of the Julio-Claudian dynasty. Both Caligula and Nero were recognised as two of the worst emperors Roman emperors.

Julio-Claudian Dynasty Julio-Claudian Dynasty

Tiberius (14 to 37 CE)

Tiberius was a moderately successful emperor, continuing many of Augustus’ social reforms and expansion. However, Tiberius never wanted to be emperor and this was evident in his attitude, this is illustrated when in 26 CE Tiberius retired from public life moving to Capri.

Caligula (37 to 41 CE)

Whilst the first six months of Caligula’s reign were highly successful he soon fell ill which resulted in extreme paranoia and erratic behaviours. He had many of his enemies, friends and family executed or exiled as well as threatening to make his horse consul of Rome.

Claudius (41 to 54 CE)

After Caligula’s death the senate tried to restore the republic. However, the Praetorian Guard installed Claudius as emperor. Whilst Claudius had many doubters in Rome he built many of Rome’s greatest structures as well as expanding the Roman Empire into Britain.

Pont du Gard Aqueduct - France Pont du Gard Aqueduct, France

Nero (54 to 68 CE)

The first half-decade of Nero’s reign was highly successful; he reduced taxes and supported the arts. However, this soon changed and he began killing those he believed to be a threat, including his mother. The most notable event of Nero’s reign is the Great Fire of Rome in 64 CE, which some accused Nero of starting so that he could build a palace.

Year of the Four Emperors

Following Nero being declared an enemy of Rome in 68 CE and his later suicide a one year civil war ensued. Within the year 69 CE there would be four emperors of Rome: Galba, Otho, Vitellius and finally Vespasian. This was the first time the Roman Empire faced uncertainty since the civil war between Octavian (Augustus) and Marc Antony.

Year of the Four Emperors - 69 CE Year of the Four Emperors (69 CE)

Galba (8 June 68 to 15 January 69 CE)

Following the death of Nero, Galba proclaimed himself emperor on the 8th of June 68CE. Whilst widely accepted by many in the empire he introduced many practices to refill the state’s treasury after Nero’s reckless spending. He ordered those who received gifts from Nero to return 90% of their value to the state, increased taxes and did not pay the army the bonuses which they were promised. This made Galba an unpopular man and resulted in his dethroning just a couple of months after he had ascended to it.

Otho (15 January 69 to 16 April 69 CE)

Otho was able to take advantage of Galba’s lack of respect for the army. Whilst Galba was making a sacrifice at the Temple of Apollo; Otho was able to talk with the leaders of the Praetorian Guard who agreed to help Otho overthrow Galba. On the same day Galba was killed and Otho installed as emperor.

However, Otho had a major problem in Vitellius. Vitellius had been raising an army since the beginning of the year and Vitellius’ legions in Germany had declared him as emperor. Otho attempted to diplomatically end the conflict. However, Vitellius marched with growing support on Rome and became emperor when Otho took his own life in April of 69 CE.

Vitellius (54 to 68 CE)

Vitellius assumed control of the Roman emperor without any further issues. He was rather peaceful in sparing those who had served under Otho. However, his reign just like his two predecessors would be a short reign.

On the first of July the legions of Vespasian in Egypt, Syria and Judaea proclaimed that Vespasian was emperor. His claim was further reinforced in August when the legions of Germania joined Vespasian and marched on Rome. The forces from Germania demolished Vitellius’ forces at the Battle of Bedriacum. The German forces continued their advance on Rome capturing it on the 20th of December 69 CE. Vespasian was accepted as emperor of the Roman Empire on the next day.

This brought an end to the ‘Year of the Four Emperors’. Vespasian founded the Flavian dynasty which brought stability back to the empire and would exist until the reign of Domitian ended in 96 CE.

Flavian Dynasty (69 to 96 CE)

The Flavian dynasty consisted of three emperors: Vespasian, Titus and Domitian. Vespasian founded the dynasty following the turmoil of the reign of Nero and the ‘Year of the Four Emperors’.

Flavian Dynasty (Vespasian, Titus, Domitian) Flavian Dynasty

Vespasian (69 to 79 CE)

When Vespasian took the role of emperor he had several objectives; to refill Rome’s treasury, establish peace throughout the empire and to install one of his son’s after his death. Vespasian succeeded in returning Rome’s financial position by increasing taxes. He also continued the conquest of Britain.

He also began several major building programmes in Rome. Most notably the Colosseum, construction started in 72 CE and was finished in 80 CE under the new emperor Titus.

Titus (79 to 81 CE)

Following the death of Vespasian his eldest son Titus assumed the emperorship. Despite being seen as a cruel and unpopular man when he became emperor he changed his outlook and ancient historians claim that his reign was one of benevolence.

Titus’ short reign was quite eventful. Under Titus the Colosseum was opened in 80 CE with one-hundred days of lavish games. However, disasters struck Titus’ reign. Firstly, Mt. Vesuvius erupted destroying the Roman cities of Pompeii and Herculaneum. Secondly, a fire which burned for three days and night burnt down much of Rome. Thirdly, a plague engulfed Rome and her territories killing a considerable portion of the Roman population.

The Colosseum The Colosseum

Domitian (81 to 96 CE)

Domitian was the second son of Vespasian and the younger brother of Titus. As emperor he was ruthless but efficient, this allowed him to significantly strengthen the Roman economy. Domitian is credited with rebuilding much of Rome following the fire which had struck in 80 CE.

His reign was highly successful. However, his relationship with the senate was not good. After he was assassinated in 96 CE the senate set off on the task of removing his reign. They destroyed statues and other monuments built in his honour.

Mid-Roman Empire (96 to 235 CE)

The Five Good Emperors (96 to 180 CE)

The period of time between 96 CE and 180 CE marks a golden period in Roman history. The empire reached its largest territorially, expanding into Dacia, Arabia and Mesopotamia.

The Five Good Emperors (96 to 235 CE) The Five Good Emperors

Nerva (96 to 98 CE)

Nerva’s reign was short lasting only two years. However, the Roman people loved the new emperor. He reduced taxes considered to be harsh. Nerva allowed those sent into exile under previous emperors to return to Rome. As well as giving the Roman people much greater freedom.

Trajan (98 to 117 CE)

Trajan’s nineteen year reign was highly successful. He had a strong relationship with the senate and was loved by the people. He expanded the Roman Empire to its greatest extents beating back the tribes of Dacia and conquering territories southeast of the Black Sea.

Trajan also set about many large building projects. Most famously, Trajan’s Column which depicts his military campaigns and still stands today. Other projects included Trajan’s Market and the Baths of Trajan.

Hadrian (117 to 138 CE)

Hadrian was the adopted son of Trajan and set about consolidating the borders of the empire. Hadrian loved the arts and invested large amounts into education throughout Rome. His most noticeable contribution was the building of Hadrian’s Wall on the English/Scottish border in order to mark out Rome’s territory.

Hadrian's Wall Hadrian's Wall

Antoninus Pius (138 to 161 CE)

Antoninus’ twenty-three year reign was one of peace. He continued many of the policies Hadrian had put in place as well as finishing the construction projects that had been started by his predecessor. Like Hadrian before him, Antoninus looked to further consolidate the frontier in Britain. He constructed the Antonine Wall north of Hadrian’s Wall in order to prevent incursions from the tribes of the north.

Marcus Aurelius (161 to 180 CE)

Marcus Aurelius was the final emperor in what was known as the era of the five good emperors. He was known as the philosopher emperor and was devoted to ruling justly. He famously wrote the book ‘Meditations’ in which he wrote many of his ideas and philosophical ideals.

Marcus Aurelius also proved himself to be highly successful as a general. He was responsible for defeating the Germanic tribes in the Marcomannic Wars as well as putting down growing military forces and revolts in the eastern parts of the empire.

Commodus & the Year of Five Emperors (180 to 193 CE)

This thirteen year period marked a bad period of time in the history of the Roman Empire. Following the era of the ‘Five Good Emperors’ it is a period of financial difficulty and civil war.

Commodus (180 to 192 CE)

Commodus was the sole remaining son of Marcus Aurelius and became co-emperor in 177 CE whilst his father was still alive. Following the death of Marcus Aurelius in 180 CE Commodus was made the sole emperor of the empire. Commodus had no interest in politics and the empire. Instead he was self-obsessed and spent his reign doing as he liked. He believed that he was the re-incarnation of Hercules and would often fight in the arena against weaker foes who would not dare touch Commodus. Commodus was eventually assassinated in 192 CE.

Year of the Five Emperors (193 CE)

The ‘Year of the Five Emperors’ was a chaotic civil war which ensued following the assassination of Commodus. The men involved were: Pertinax, Didius Julianus, Pescennius Niger, Clodius Albinus and Septimius Severus.

Year of the Five Emperors (193 CE) Year of the Five Emperors

Pertinax was proclaimed to be emperor by the senate shortly after Commodus’ death. However, Pertinax rescinded many of the perks that the Praetorian Guard had been granted by Commodus and was subsequently killed in a plot organised by the Praetorian Guard. Didius Julianus followed but was widely disliked by those in Rome and was executed when Septimius Severus arrived in Rome and was subsequently named emperor.

Civil war broke out when Pescennius Niger who had legions in the eastern provinces declared himself emperor. Septimius Severus looked to Clodius Albinus for support and made him co-emperor. This allowed Septimius to raise his legions and fight Pescennius Niger in a war that would last for two years. Septimius Severus was victorious and this brought an end to the chaotic year. Septimius Severus would found the Severan Dynasty which would continue to rule the Roman Empire for four decades.

Severan Dynasty (193 to 235 CE)

The Severan dynasty consisted of six emperors from the year 193 CE to 235 CE. It followed a period of turmoil and restored an element of peace to the Roman Empire.

Severan Dynasty (Caracalla, Geta, Marcrinus, Elagabalus, Severus Alexander) Severan Dynasty

Septimius Severus (193 to 211 CE)

Septimius’ reign was largely successful. After three years of co-emperorship with Clodius Albinus he fought a successful war against him making Septimius the sole ruler of the empire. He also expanded Roman territories in the east to the River Tigris. Towards the end of Septimius’ reign he introduced his sons: Caracalla and Geta as co-emperors in order to ensure a smooth transition of power.

Arch of Septimius Severus Arch of Septimius Severus

Caracalla and Geta (198 to 217 CE)

Caracalla, the older brother of Geta became co-emperor with his father in 198 CE he would rule until 217 CE. His younger brother, Geta, became co-emperor in 209 CE, however, shortly after his father Septimius died his older brother Caracalla had Geta murdered in order to gain sole control over the Roman Empire.

Caracalla’s reign was not remembered to fondly. He is mostly remembered for the large-scale persecutions he ordered in Rome and elsewhere in the empire. Caracalla did however grant citizenship to all those living within the empire’s borders, however, it is likely this was done in order to increase tax revenue.

The Pantheon The Pantheon

Macrinus - 217 to 218 CE

Following the rather bloody reign of Caracalla, it is believed that it was Macrinus the next emperor who had assassinated Caracalla. He was not hugely popular with the soldiers, as he retracted many of their benefits which had been previously awarded by Caracalla. He also had a poor track record in war. Avoiding conflict in Armenia and Dacia whilst losing a conflict with the Parthians. Interestingly, during Macrinus’ one year reign he never stayed or visited Rome.

Elagabalus 218 to 222 CE

Elagabalus was claimed to be the true heir to the Roman Empire following the death of Caracalla. Thus, Macrinus was executed due to his inability to gain the support of the army, the senate or the people of Rome. However, his reign of the empire lasted only four years and was marred in controversy. At the young age of just eighteen he was assassinated and replaced by his cousin Severus Alexander.

Severus Alexander - 222 to 235 CE

Severus’ thirteen year reign was relatively successful. He was able to repel the threat of the Sassanid’s and provided prosperity in Rome. However, he was assassinated in 235 CE due to his attempts to negotiate with Germanic tribes. This led to a plot from within the army which was successful. Severus Alexander’s death brought an end to the Severan dynasty and started the ‘Crisis of the Third Century’ which would involve fifty years of civil war and strife which would bring the Roman Empire to its knees.

Crisis of the Third Century (235 to 284 CE)

Following the assassination of Severus Alexander the Roman Empire was plunged into a fifty year era known as the ‘Crisis of the Third Century’. The empire faced barbarian incursions, disease, famine, civil wars and economic difficulty. In this fifty year period there were twenty-six people who were appointed as emperor.

Civil War

With no clear rule of succession the emperorship was up for grabs. This resulted in the legions of generals appointing their general as emperor. This led to dozens of civil wars and also meant that the borders of the Roman Empire were neglected. Allowing invasions from the Goths, Vandals and other tribespeople.

Following the death of the Valerian in 260 CE, the Roman Empire was split into three smaller emperors: the Gallic Empire, Palmyrene Empire and the remaining territories belonged to Rome. It was not until 274 CE that the Roman Empire was united back into a single entity.

Barbarian Invasions

The relationship with the Germanic tribespeople had always been difficult. During this era there were less legions available in order to keep order in the region. There was also a series of bad harvests which made life difficult for the Germanic peoples. This resulted in the tribes aggressively moving into Roman territories in order to find better land to farm.

The eastern regions of the empire were also troublesome. The Sassanid Empire was growing stronger and began to infringe on Roman territories. This led to a series of defeats for the Roman army and significant loss of territory.


Around 250 CE, the Plague of Cyprian caused widespread death across the empire. The plague continued to haunt the Roman Empire until around 270 CE. At one point it’s claimed that more than five-thousand people were dying every day in Rome alone.


The events of the ‘Crisis of the Third Century’ meant the strain on the economy was significant. The Roman Empire was largely dependent on trade. However, roads became a lot more dangerous which meant that merchants could not travel to sell their wares.

The many emperors of the period also had to constantly devalue the currency in order to raise finances. This led to high inflation and essentially sent the Roman economy into the gutter. The large loss of life caused through invasion, plague and war also meant that demand for goods fell significantly.

End of the Crisis

Aurelian, emperor between 270 CE and 275 CE, was successful in re-uniting the Roman Empire. However, it was not until Diocletian in 284 CE that the ‘Crisis of the Third Century’ was brought to an end. His twenty-one year reign brought stability back to the empire and he sought to solve many of the issues which had been rampant in this era of crisis. Whilst Diocletian restored peace to the Roman Empire these problems would continue to resurface until the eventual fall of the Western Roman Empire in 476 CE.

Late Empire (284 to 395 CE)

Diocletian (284 to 305 CE)

It was Diocletian who brought an end to the ‘Crisis of the Third Century’. Following his ascension to the role of emperor he introduced several polices to remedy many of the issues that had caused anarchy throughout the empire. He brought in several economy reforms in order to fix the broken Roman economy. His most important reform was the ‘tetrarchy’. This meant that the empire was ruled by four persons appointed by the emperor with a dedicated heir appointed before the death of an emperor.

Baths of Diocletian Baths of Diocletian

Constantine the Great (307 to 337 CE)

Constantine the Great came to the throne following a bitter civil war in which he overcame other contenders to the emperorship. His most notable impact on the empire was the conversion from traditional Roman gods to Christianity. He also introduced new coinage, which would be used for almost a thousand years until the fall of the Byzantine Empire.

Arch of Constantine Arch of Constantine

Theodosius I (379 to 395 CE)

Theodosius I was the last Roman emperor to rule over both the western and eastern parts of the empire. As emperor he took several steps to rid the empire of pagan gods and strengthened Christianity as the predominant religion. Following the death of Theodosius I the Roman Empire began to decline and would eventually fall at the hands of barbarian invaders.

Late Roman Emperors (Diocletian, Constantine the Great, Theodosius I) Late Roman Emperors

Fall of the Empire (395 to 476 CE)

Many of the issues faced during the ‘Crisis of the Third Century’ reappeared after 395 CE and in greater severity. Barbarian invasions began to occur with greater frequency and greater success. The economy shrank and the military decreased in power. Also the introduction of Christianity meant that traditional Roman ideals were lost.

Crossing of the Rhine (406 CE)

In 406 CE, multiple Germanic tribes crossed the Rhine into Roman territories in order to find safer lands which were easier to live on. The Suebi, Alans and Vandals all crossed with their numbers in excess of 100,000. The Romans had no choice but to let them settle in the empire. They were granted territories in Hispania.

Visigoths Sack Rome (410 CE)

The capital of the Roman Empire had been moved from Rome to Ravenna eight years prior to the sack. However, the fact that barbarians were able to march so far into Roman territories shows the dire state of affairs. Prior to sacking Rome the Visigoths had rampaged across the Greek provinces causing mayhem throughout the area.

Loss of Territories

In 410 CE, the Romans were forced to retreat from Britannia as they did not have the military power to maintain the province. Further territories were lost in northern Gaul. Whilst most of Hispania had been lost to Germanic settlers. Further territories were lost in northern Africa. The Vandals seized Carthage in 439 CE, this was a significant loss to the Roman Empire as Carthage was a major trading post within the empire.

Roman Army in Decline

The Roman army during the period was utterly shambolic. Both training and organisation were disregarded. The army faced defeat on a regular basis in the late fourth and fifth centuries. This meant that instead of defeating invaders the emperor and senate were constantly paying great amounts of wealth to barbarians in order to cease their attacks.

Vandals Sack Rome (455 CE)

In 455 CE, Rome was once again subjected to being sacked. This second sack within the century however was relatively ‘peaceful’. There was minimal killing and the city remained largely unharmed. This demonstrates the complete and utter inability for the Roman army to mount any defence against barbarian invaders.

Final Sack of Rome and Fall of the Roman Empire (476 CE)

In 476 CE, Odoacer invaded Italy and brought an end to the Western Roman Empire. The last emperor Romulus Augustulus was removed from power but his life was spared. Western Europe was now controlled by barbarian forces. However, the Byzantine Roman Empire in the east continued to prosper for many centuries to follow. The Byzantine Empire at its height re-conquered much of Western Europe in later centuries.

Sack of Rome Sack of Rome

Legacy of the Roman Empire

  • Latin
    The official language of the Roman Empire is still prevalent to this day. It had a large impact on the ‘romance languages’: Italian, Spanish, Portuguese and French. We also see many Latin words within the English language. In the fifteenth century, a thousand years after the fall of the Western Roman Empire over 70% of books were still written in Latin.
  • Calendar
    Our modern-day twelve month calendar was introduced by Julius Caesar over two-thousand years ago. The months used were: Ianuarius, Februarius, Mercedonius, Martius, Aprilis, Maius, Iunius, Quintilis, Augustus, September, October, November and December.
  • Numerals
    The Roman method of counting was used across Europe until the fourteenth century. However, Roman numerals continue to be used in the twenty-first century for various reasons.
  • Religion
    Christianity was promoted to the sole religion of the Roman Empire in the fourth century. The efforts of Constantine the Great and Theodosius I meant that Christianity spread quickly throughout Europe and beyond.
  • Architecture
    The Romans made many major inventions and innovations in the field of architecture. These developments allowed the creation of structures such as the Colosseum and the Pantheon. Roman architecture strongly influenced the building styles for millennia to follow.
  • Medical Practices
    The Romans adopted many Greek and Egyptian medical practices. They continued to innovate and improve these which were then inherited by future civilisations.

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