Complex sentence: He continued to hold the lands in North Wales and Cardiganshire which he had inherited, until his death in 1311 when they passed into the hands of his son Goronwy ap Tudur Hen.
Split into simpler sentences: He continued to hold the lands in North Wales and Cardiganshire which he had inherited. Upon his death in 1311, his holdings passed into the hands of his son Goronwy ap Tudur Hen.