Introduction
Gratian or Gratianus (died 407) was a Roman usurper (407) in Roman Britain.
Career
Following the death of the usurper Marcus, Gratian was acclaimed as emperor by the army in Britain in early 407. His background, as recorded by Orosius, was that he was a native Briton and one of the urban aristocracy. His rule coincided with a huge barbarian invasion that had afflicted Gaul, possibly with the connivance of Stilicho, the Emperor Honorius’s magister militum, who was concerned about the British usurpers. On the last day of December 406, an army of Vandals, Alans and Suebi (Sueves) had crossed the frozen Rhine. During 407, they spread across northern Gaul towards Boulogne, and Zosimus wrote that the troops in Britain feared an invasion across the English Channel.
The army wanted to cross to Gaul and stop the barbarians but Gratian ordered them to remain. Unhappy with this, the troops killed him after a reign of four months and chose Constantine III as their leader.
Geoffrey of Monmouth describes a similar character, named Gracianus Municeps, who is likely the same figure.
In literature
Gratian is a major character in Alfred Duggan's 1951 novel The Little Emperors.