The Great Conspiracy is a term given to a year-long war that occurred in Roman Britain

Roman Britain

Roman Britain was the part of the island of Great Britain controlled by the Roman Empire from AD 43 until ca. AD 410.The Romans referred to the imperial province as Britannia, which eventually comprised all of the island of Great Britain south of the fluid frontier with Caledonia...

 near the end of the Roman occupation of the island. The historian Ammianus Marcellinus

Ammianus Marcellinus

Ammianus Marcellinus was a fourth-century Roman historian. He wrote the penultimate major historical account surviving from Antiquity...

 described it as a barbarica conspiratio that capitalized on a depleted military force in the province brought about by Magnentius

Magnentius

Flavius Magnus Magnentius was a usurper of the Roman Empire .-Early life and career:...

' losses of the Battle of Mursa Major

Battle of Mursa Major

The Battle of Mursa Major was fought in 351 between the Eastern Roman army led by Constantius II and the western forces supporting the usurper Magnentius.The action took place along the valley of the Drava River, a Danube tributary in present day Croatia....

 after his unsuccessful bid to become emperor.

The conspiracy

In the winter of 367

367

Year 367 was a common year starting on Monday of the Julian calendar. At the time, it was known as the Year of the Consulship of Lupicinus and Iovanus...

, the Roman garrison on Hadrian's Wall

Hadrian's Wall

Hadrian's Wall was a defensive fortification in Roman Britain. Begun in AD 122, during the rule of emperor Hadrian, it was the first of two fortifications built across Great Britain, the second being the Antonine Wall, lesser known of the two because its physical remains are less evident today.The...

 rebelled, and allowed Picts

Picts

The Picts were a group of Late Iron Age and Early Mediaeval people living in what is now eastern and northern Scotland. There is an association with the distribution of brochs, place names beginning 'Pit-', for instance Pitlochry, and Pictish stones. They are recorded from before the Roman conquest...

 from Caledonia

Caledonia

Caledonia is the Latinised form and name given by the Romans to the land in today's Scotland north of their province of Britannia, beyond the frontier of their empire...

 to enter Britannia. Simultaneously, Attacotti

Attacotti

Attacotti refers to a people who despoiled Roman Britain between 364 and 368, along with Scotti, Picts, Saxons, Roman military deserters, and the indigenous Britons themselves. The marauders were defeated by Count Theodosius in 368...

, the Scotti

Scoti

Scoti or Scotti was the generic name used by the Romans to describe those who sailed from Ireland to conduct raids on Roman Britain. It was thus synonymous with the modern term Gaels...

 from Hibernia

Hibernia

Hibernia is the Classical Latin name for the island of Ireland. The name Hibernia was taken from Greek geographical accounts. During his exploration of northwest Europe , Pytheas of Massilia called the island Ierne . In his book Geographia Hibernia is the Classical Latin name for the island of...

, and Saxons

Saxons

The Saxons were a confederation of Germanic tribes originating on the North German plain. The Saxons earliest known area of settlement is Northern Albingia, an area approximately that of modern Holstein...

 from Germania

Germania

Germania was the Greek and Roman geographical term for the geographical regions inhabited by mainly by peoples considered to be Germani. It was most often used to refer especially to the east of the Rhine and north of the Danube...

, landed in coordinated and pre-arranged waves on the island's mid-western and south-eastern borders, respectively. Franks

Franks

The Franks were a confederation of Germanic tribes first attested in the third century AD as living north and east of the Lower Rhine River. From the third to fifth centuries some Franks raided Roman territory while other Franks joined the Roman troops in Gaul. Only the Salian Franks formed a...

 and Saxons also landed in northern Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

.

These warbands managed to overwhelm nearly all of the loyal Roman outposts and settlements. The entire western and northern areas of Britannia were overwhelmed, the cities sacked and the civilian Romano-British

Romano-British

Romano-British culture describes the culture that arose in Britain under the Roman Empire following the Roman conquest of AD 43 and the creation of the province of Britannia. It arose as a fusion of the imported Roman culture with that of the indigenous Britons, a people of Celtic language and...

 murdered, raped, or enslaved. Nectaridus

Nectaridus

Nectaridus was a possible early Count of the Saxon Shore, a military leader in Roman Britain in the later fourth century AD.His command may have been an ad hoc creation, possibly during the reign of Valentinian I or Julian during the early 360s in response to growing pirate raiding...

, the Count of the Saxon Shore

Count of the Saxon Shore

The Count of the Saxon Shore for Britain was the head of the "Saxon Shore" military command of the later Roman Empire.The post was possibly created during the reign of Constantine I and was probably existent by AD 367 when Nectaridus is elliptically referred to as one by Ammianus...

, was killed and the Dux Britanniarum

Dux Britanniarum

Dux Britanniarum was a military post in Roman Britain, probably created by Diocletian or Constantine I during the late third or early fourth century....

, Fullofaudes

Fullofaudes

Fullofaudes was a Dux Britanniarum, a military leader in Roman Britain in the later fourth century.He was either killed or besieged by the barbarian invaders during the Great Conspiracy and replaced by Dulcitius when Count Theodosius came in Britain in 369 to restore order.He was probably defeated...

, was either besieged or captured, the remaining loyal army units staying garrisoned inside southeastern cities. The areani

Areani

The areani were agents for the Roman Empire, based in Roman Britain during the later part of the Roman occupation of the island. They helped to instigate the Great Conspiracy...

or local agents whom the Romans paid to provide intelligence on barbarian movements seem to have betrayed their paymasters for bribes, making the attacks completely unexpected. Deserting soldiers and escaped slaves roamed the countryside and turned to robbery to support themselves. Although the chaos was widespread and initially concerted, the aims of the rebels were simply personal enrichment and they worked as small bands rather than larger armies.

Roman response

Emperor Valentinian I

Valentinian I

Valentinian I , also known as Valentinian the Great, was Roman emperor from 364 to 375. Upon becoming emperor he made his brother Valens his co-emperor, giving him rule of the eastern provinces while Valentinian retained the west....

 was campaigning against the Alamanni

Alamanni

The Alamanni, Allemanni, or Alemanni were originally an alliance of Germanic tribes located around the upper Rhine river . One of the earliest references to them is the cognomen Alamannicus assumed by Roman Emperor Caracalla, who ruled the Roman Empire from 211 to 217 and claimed thereby to be...

 at the time and unable to respond personally. A series of commanders to act in his stead were chosen but swiftly recalled. The first was Severus

Severus

Emperors in the Severan dynasty*Septimius Severus , Roman Emperor from 193 to 211*Alexander Severus , Roman Emperor from 222 to 235*Flavius Valerius Severus , Roman Emperor from 306 to 307Other individuals...

, the emperor's comes domesticorum, soon replaced by Jovinus

Jovinus

Jovinus was a Gallo-Roman senator and claimed to be Roman Emperor .Following the defeat of the usurper known with the name of Constantine III, Jovinus was proclaimed emperor at Mainz in 411, a puppet supported by Gundahar, king of the Burgundians, and Goar, king of the Alans...

, the magister equitum; rumours of disasters dogged them, however, and it took almost 15 months before a capable replacement was sent.

In the spring of 368

368

Year 368 was a leap year starting on Tuesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus and Valens...

, a relief force commanded by Count Theodosius

Count Theodosius

Flavius Theodosius or Theodosius the Elder was a senior military officer serving in the Western Roman Empire. He achieved the rank of Comes Britanniarum and as such, he is usually referred to as Comes Theodosius...

 arrived in Britannia from Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

. He brought with him four units, Batavi

Batavi (military unit)

The Batavi was an auxilia palatina unit of the Late Roman army, active between the 4th and the 5th century. It was composed by 500 soldiers and was the heir of those ethnic groups that were initially used as auxiliary units of the Roman army and later integrated in the Roman Empire after the...

, Heruli

Heruli (military unit)

The Heruli was an auxilia palatina unit of the Late Roman army, active between the 4th and the 5th century. It was composed of 500 soldiers and was the heir of those ethnic groups that were initially used as auxiliary units of the Roman army and later integrated in the Roman Empire after the...

, Iovii and Victores as well as his son, the later Emperor Theodosius I

Theodosius I

Theodosius I , also known as Theodosius the Great, was Roman Emperor from 379 to 395. Theodosius was the last emperor to rule over both the eastern and the western halves of the Roman Empire. During his reign, the Goths secured control of Illyricum after the Gothic War, establishing their homeland...

 and probably the later usurper

Roman usurper

Usurpers are individuals or groups of individuals who obtain and maintain the power or rights of another by force and without legal authority. Usurpation was endemic during roman imperial era, especially from the crisis of the third century onwards, when political instability became the rule.The...

 Magnus Maximus

Magnus Maximus

Magnus Maximus , also known as Maximianus and Macsen Wledig in Welsh, was Western Roman Emperor from 383 to 388. As commander of Britain, he usurped the throne against Emperor Gratian in 383...

. He marched from Richborough

Richborough

Richborough is a settlement north of Sandwich on the east coast of the county of Kent, England. Richborough lies close to the Isle of Thanet....

 to Londinium

Londinium

The city of London was established by the Romans around AD 43. It served as a major imperial commercial centre until its abandonment during the 5th century.-Origins and language:...

 and began to deal with the invaders. An amnesty

Amnesty

Amnesty is a legislative or executive act by which a state restores those who may have been guilty of an offense against it to the positions of innocent people, without changing the laws defining the offense. It includes more than pardon, in as much as it obliterates all legal remembrance of the...

 was promised to deserters which enabled Theodosius to regarrison abandoned forts. A new Dux Britanniarum

Dux Britanniarum

Dux Britanniarum was a military post in Roman Britain, probably created by Diocletian or Constantine I during the late third or early fourth century....

 was appointed, Dulcitius

Dulcitius

Dulcitius was a Dux Britanniarum, a military leader in Roman Britain in the later fourth century AD. He is praised by Ammianus for his military abilities....

, with Civilis

Civilis (vicarius)

Civilis is all that is known of the name of a vicarius of Roman Britain around AD 368. Dulcitius was appointed Dux Britanniarum at the same time under Count Theodosius' reforms....

 granted vicarius

Vicarius

Vicarius is a Latin word, meaning substitute or deputy. It is the root and origin of the English word "vicar" and cognate to the Persian word most familiar in the variant vizier....

 status to head a new civilian administration.

By the end of the year, the barbarians had been driven back to their homelands; the mutineers had been executed; Hadrian's Wall was retaken; and order returned to the diocese. Considerable reorganization was undertaken in Britain, including the creation of a new province named Valentia

Valentia (Roman Britain)

Valentia was the name of a consular northern province of Roman Britain.-History:Count Theodosius set up Valentia in 369 AD as part of his reorganisation of Britain following the Great Conspiracy, and probably named it after the reigning emperors, Valentinian and Valens.Ammianus tells of how the...

, probably to better address the state of the far north. Claudian

Claudian

Claudian was a Roman poet, who worked for Emperor Honorius and the latter's general Stilicho.A Greek-speaking citizen of Alexandria and probably not a Christian convert, Claudian arrived in Rome before 395. He made his mark with a eulogy of his two young patrons, Probinus and Olybrius, thereby...

 suggests that naval activity took place in northern Britain. It is possible that Theodosius mounted punitive expeditions against the barbarians and extracted terms from them. Certainly, the Notitia Dignitatum

Notitia Dignitatum

The Notitia Dignitatum is a unique document of the Roman imperial chanceries. One of the very few surviving documents of Roman government, it details the administrative organisation of the eastern and western empires, listing several thousand offices from the imperial court down to the provincial...

 later records four units of Attacotti

Attacotti

Attacotti refers to a people who despoiled Roman Britain between 364 and 368, along with Scotti, Picts, Saxons, Roman military deserters, and the indigenous Britons themselves. The marauders were defeated by Count Theodosius in 368...

 serving Rome on the continent. The areani were removed from duty and the frontiers refortified with co-operation from border tribes such as the Votadini

Votadini

The Votadini were a people of the Iron Age in Great Britain, and their territory was briefly part of the Roman province Britannia...

, marking the career of men such as Paternus

Padarn Beisrudd

Padarn Beisrudd ap Tegid literally translates as Paternus of the Scarlet Robe, son of Tegid. His father may have borne the Roman name of Tacitus. Padarn is believed to have been born in the early 4th century in the Old North of Roman Britain...

.

Political effects

Theodosius returned to Rome a hero, and was made senior military advisor to Valentinian I. A decade later, his son became emperor. The Romans were able to end much of the chaos, though raids by all of the people listed above did continue.

Fictional references

Fictional accounts of the Great Conspiracy were featured in Wallace Breem

Wallace Breem

Wallace Breem was a British librarian and author. He was the Librarian and Keeper of Manuscripts of the Inner Temple Law Library, and wrote historical novels, including Eagle in the Snow ....

's historical novel Eagle in the Snow

Eagle in the Snow

Eagle in the Snow is a historical fiction novel. Written in 1970 by Wallace Breem, the novel is set in Britannia and Germania in the late 4th and early 5th century, and centres on the Roman general Paulinus Gaius Maximus, a Mithraic in an age of Christianization...

, Stephen R. Lawhead

Stephen R. Lawhead

Stephen R. Lawhead, born , is a best-selling American writer known for his works of fantasy, science fiction, and more recently, historical fiction, particularly Celtic historical fiction...

's fantasy novel Taliesin, and Jack Whyte's historical novel, The Skystone

The Skystone

The Skystone is a historical fiction novel written by Jack Whyte, which was first published in 1992. The story is told by a Roman Officer called Publius Varrus, who is an expert blacksmith as well as a soldier...

.