رودولف الأول
John was born shortly before or after the death of his father Rudolf II, the younger son of King Rudolf I of Germany. His mother was Agnes, daughter of King Ottokar II of Bohemia. He passed his early days at the Bohemian court and the town of Brugg in the Swabian home territory of the Habsburgs, where he is mentioned as titular duke in a 1294 deed.