5th century

The  was a century only sporadically visited by the Doctor. The Seventh Doctor once stopped off in 5th century Britain for chestnuts in his game of conkers. (COMIC: Doctor Conkerer!)

The Roman occupation of Britain, which had begun in 43, ended during the early years of the century. (AUDIO: The Wrath of the Iceni)

Behind the scenes
The Dalek Handbook dates the beginning of the Thousand Year War on Skaro to circa 450, which is derived from numerous assumptions and inferences: However, this dating is contested, with numerous editions of AHistory dating the start of the war to 240 BC, and the in-universe short story Peaceful Thals Ambushed! alternatively dating the events of The Daleks to 2064.
 * That The Daleks and Genesis of the Daleks are separated by approximately 500 years, based on dialogue from the former story concerning the dating of the neutronic war.
 * That The Daleks takes place circa 1963, assuming the First Doctor returned Ian and Barbara to the right time period after An Unearthly Child but not the right place.
 * That Genesis therefore takes place circa 1450, and that the Thousand Year War, which ends in that story, literally lasted (or at lasted very close to) 1,000 years.