The significant battle in 1066 that changed the course of English history is the Battle of Hastings. Fought on October 14, 1066, it was the decisive conflict between the Norman forces led by Duke William of Normandy and the English army commanded by King Harold II. Harold's defeat resulted in his death and the end of Anglo-Saxon rule in England. William's victory marked the beginning of Norman England and led to profound changes in the English culture, language, and governance. The battle's outcome established the Norman lineage, shifting power dynamics and influencing the historical trajectory of Britain profoundly.