jan 1, 410 - [British Empire] Romans left Britannia and was invaded by Anglo-Saxons

Description:

Jutes, Frisians, Saxons (northern Germany) & Angles (southern Denmark) settled in the eastern and southern shores of Britannia.
West England, Wales & Cornwall was still inhabited by Britons (Romano-British people).
Many Britons left Britannia from the 4th century on across the English Channel and started settling in Gaul (north Italy, France, Belgium, western Switzerland, Netherlands & little of Germany). The new nation was called Brittany and the language Breton, still in use nowadays.