Its strategic position and comparative seclusion from its surroundings no doubt played a part in the decision to found a monastery there in the sixth century. Its foundation is popularly credited to St. Columba or Colmcille after which it took its second name, Doire Colmcille. Recent research has cast doubts on the authenticity of this claim and suggests an alternative founder. Nevertheless it was an important part of the Columban federation of monasteries and it was from Derry that Columba would depart on his mission to take the Christian message to Scotland and the North of England. Catholic and Protestant traditions both cherish their Columban heritage.
Doire Colmcille it remained from the tenth to the early seventeenth centuries but plans, for the extension of Tudor control over the whole of the island of Ireland, were to change the function of monastic Derry.