When did the last successful foreign invasion of England take place?

The year 1066 is hugely significant in English history because it marks the Norman Conquest. Before 1066, England was ruled by Anglo-Saxon kings. In January of that year, King Edward the Confessor died without a clear heir, leading to a power struggle. William, Duke of Normandy, claimed he had been promised the throne. He invaded England in September 1066, and his forces met the English army, led by King Harold, at the Battle of Hastings in October. William's victory at Hastings resulted in the Norman takeover of England. William became King William I, also known as William the Conqueror, and this event dramatically changed English society, language, and law. While there have been attempted invasions since, none have been successful in conquering the country. That's why 1066 is the answer; it represents the last time a foreign power successfully invaded and took control of England.