 However, after Otto's death in 1200, the House of Hohenstaufen was forced to withdraw from the Aargau.By way of two neighbouring aristocratic houses (Andechs-Merania and Châlon), in about 1230 Lenzburg castle came by marriage into the possession of the Counts of Kyburg.They then founded a fortified market settlement at the western base of the castle hill, today's town of Lenzburg.