Albert VII
During this period of French rule, the defences of the fortress were strengthened by the famous siege engineer Vauban. The French king's great-grandson Louis (1710–74) was, from 1712, the first heir-general of Albert VII. Albert VII was a descendant of Anna of Bohemia and William of Thuringia, having that blood through his mother's Danish great-great-grandmother, but was not the heir-general of that line. Louis was the first real claimant of Luxembourg to descend from both sisters, the daughters of Elisabeth of Bohemia, the last Luxembourg empress.