John I, Duke of Brabant was a nobleman who ruled from 1285 to 1294. He was born in 1252 and was a member of the House of Reginar. John I was known for his efforts to strengthen the duchy and improve its governance during his reign. He was the son of Henry III, Duke of Brabant and Adelaide of Burgundy. John I's rule was marked by his attempts to maintain peace and stability in the region, as well as his involvement in various political alliances. His reign ended when he died in 1294, after which he was succeeded by his son, John II.