Why did the Romans leave Britain and Anglo Saxons come?

The Romans withdrew from Britain around 410 AD primarily due to the decline of the Roman Empire, which faced internal strife and external pressures, including invasions by various tribes. With Roman legions pulled back to defend other parts of the empire, Britain became vulnerable to invasions. The Anglo-Saxons, a group of Germanic tribes, began migrating to Britain during this power vacuum, drawn by opportunities for land and settlement. Their arrival marked the beginning of a new era in British history, as they established kingdoms and significantly influenced the culture and society of the region.