Complex sentence: Condé himself held Burgundy, Berry and the marches of Lorraine, as well as other less important territory; his brother Conti held Champagne, his brother-in-law, Longueville, Normandy.
Split into simpler sentences: Condé himself held Burgundy, Berry and the marches of Lorraine, as well as other less important territory. His brother Conti held Champagne, his brother-in-law, Longueville, Normandy.