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The Romans held Britain from the invasion of Julius Caesar till their voluntary withdrawal from the island, A.D. 420,- that is, about five hundred years.

Thomas Bulfinch (1858). “The Age of Chivalry: Or Legends of King Arthur, "King Arthur and His Knights", "The Mabinogeon", "The Crusades", "Robin Hood", Etc”, p.196
The Romans held Britain from the invasion of Julius Caesar till their voluntary withdrawal from the island, A.D. 420,- that is, about five hundred years.