The significant event that occurred in 1066 in England is the Norman Conquest, marked by the Battle of Hastings. Led by William the Conqueror, Duke of Normandy, the invasion resulted in the defeat of King Harold II of England. This pivotal moment transformed English society, government, and culture, with the Normans implementing feudalism, reshaping land ownership, and influencing the English language with French. The conquest solidified William's rule, fundamentally altering the course of English history and shaping future political and social structures in the realm.