Which 1066 event greatly increased French influence on English?

The 1066 event that greatly increased French influence on English was the Norman Conquest.

William, Duke of Normandy, invaded England after the disputed succession that followed the death of Edward the Confessor. William’s army defeated King Harold Godwinson at the Battle of Hastings on 14 October 1066, and William was crowned king later that year. Although resistance and rebellions continued for years, the conquest permanently changed England’s ruling class.

After the takeover, Anglo-Norman French became the language of the court, administration, and much of the aristocracy, while ordinary people continued to speak varieties of English. This long period of social bilingualism helped bring thousands of French words into English, especially in government, law, warfare, cuisine, and social rank. Examples include court, judge, prison, army, beef, and mutton.

The conquest did not instantly replace English. English survived among the wider population and gradually absorbed French vocabulary and other influences before re-emerging as the dominant language. The resulting Middle English was substantially different from Old English. The Hundred Years’ War began much later, the Wars of the Roses occurred in the fifteenth century, and the Glorious Revolution took place in 1688.