Fullofaudes was a 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....

, a military leader 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...

 in the later fourth century.

He was either killed or besieged by the barbarian invaders during the Great Conspiracy

Great Conspiracy

The Great Conspiracy is a term given to a year-long war that occurred in Roman Britain near the end of the Roman occupation of the island. The historian Ammianus Marcellinus described it as a barbarica conspiratio that capitalized on a depleted military force in the province brought about by...

 and replaced by 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....

 when 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...

 came in Britain in 369 to restore order.

He was probably defeated in the north of Britain; the outpost forts north of 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...

 were abandoned at this time. It may be that his own troops rebelled under him and switched allegiance to the enemy, Ammianus' description is unclear.