Duke John I, also known as John of Brabant, was a nobleman who ruled as the Duke of Brabant from 1355 until his death in 1361. He was born in 1300 and was a member of the House of Reginar. His reign was marked by efforts to strengthen the duchy's economy and political influence in the region. John I was also known for his role in the Burgundian Netherlands, as he was the father of Philip the Bold, who later became the first Duke of Burgundy. His lineage played a significant part in the political landscape of medieval Europe, influencing alliances and territorial control.