- The Great Conspiracy(367-8 CE) occurred in Northern Britannia during the reign of Valentinian I
- It was a combined invasion of Britannia that took place by an alliance of the Scots, Picts and Saxons, which lasted for one year. They were defeated by General Theodosius.
The Buildup
- The Garrisons on Hadrian's Wall rebelled, and allowed an invasion of the Picts to pass through.
- They were demoralised after Britannia had been depleted of troops by the Usurper Magnentius who had used them in 351 CE for the Battle of Mursa Major, on the R. Drava (Croatia) the bloodiest civil war of the Roman Empire.
The Invasions were planned and timed in waves
- Simultaneously, the Attacotti and the Scotti from Hibernia landed on the western coast and the Saxons from Germania landed on the Eastern coast. The Franks and Saxons also invaded northern Gaul.
- The landings were co-ordinated and planned in prearranged waves.
- Western and Northern Britannia was occupied, after all resistance was overcome and the cities of Britannia sacked.
- The Count of the Saxon Shore, Nectaridus and the Dux Britanniarum, Fullofaudes, who controlled Hadrian's Wall from York, were killed.
General Theodosius and the end of the Great Conspiracy
- Despite initial difficulties, the invasion was defeated when Valentinian I sent General Theodosius in 368 CE.
- General Theodosius took several Legions and landed at Richborough before moving to London. Theodosius restored Roman Rule and quelled another rebellion, staying on to rebuild the fortifications, and establish a fifth Province called Valentia.
- General Theodosius left Britannia in 369 CE.
Hadrian’s Wall