# Constantine III is proclaimed emperor in Britain (407)

URL: https://english-history.com/timeline/407-constantine-iii-is-proclaimed-emperor-in-britain
Categories: ruler-change

British-based troops elevated Constantine III, who crossed to Gaul with much of the remaining field army. Within the broader Roman Britain period, conquest, provincial administration, urbanization, frontier warfare and the gradual weakening of imperial rule reshaped the island. This event is placed at AD 407 in the chronology so it can be read alongside the political, military, social and cultural changes around it. The move accelerated the collapse of effective imperial government in Britain.

## Why it matters
The move accelerated the collapse of effective imperial government in Britain.

Ruler at the time: [Roman Britain](https://english-history.com/rulers/roman-britain)

## Sources
- [Wikipedia topic lookup — Constantine III is proclaimed emperor in Britain](https://en.wikipedia.org/wiki/Special:Search?search=Constantine+III+is+proclaimed+emperor+in+Britain&go=Go)
- [Encyclopaedia Britannica topic lookup — Constantine III is proclaimed emperor in Britain](https://www.britannica.com/search?query=Constantine+III+is+proclaimed+emperor+in+Britain)
- [Wikipedia — Timeline of British history](https://en.wikipedia.org/wiki/Timeline_of_British_history_%28before_1000%29)
- [Encyclopaedia Britannica — Roman Britain topic search](https://www.britannica.com/search?query=Roman%20Britain)