Which of the invasions, happened in the early history of GB and in the Middle ages

The Norman conquest of England was the invasion and occupation of England by an army of Normans and French led by Duke William II of Normandy in the 11th century. William, who defeated King Harold IIof England on 14 October 1066, at the Battle of Hastings, was crowned king at London on Christmas Day, 1066. http://en.wikipedia.org/wiki/Norman_conquest_of_England