 Ulrich IV, the last Count of Lenzburg, named Emperor Friedrich I Barbarossa as his personal heir in his will; they had been on the Second Crusade together.The emperor came to Lenzburg Castle and personally supervised the division of the estate, giving a majority of the lands to his son, the Count palatine Otto of Burgundy.However, after Otto's death in 1200, the House of Hohenstaufen was forced to withdraw from the Aargau.