Augustus Jessup had the granary demolished and the tower returned to its original state. The well, first mentioned in 1369, was left in the open once more. During the renovation of 1978–86, the division of the floors and connection to the stairs were rearranged to accommodate part of the Historical Museum. Knights' Hall The construction of the Knights' Hall began in 1339 under Habsburg rule. Duke Frederick II of Tyrol-Austria intended to marry the daughter of King Edward III of England at Lenzburg Castle, and thus ordered a suitable Gothic residential building to be erected. However, the young duke died in 1344 shortly before work could be completed, and the walls remained unplastered. In 1508 the western part was in such bad condition that it had to be demolished and rebuilt. In the eastern part the exterior walls were left standing, but the interior was completely rearranged here, too. The building received new rafters and several columns to improve its load-bearing capacity, and the walls were now plastered. The length of the building was somewhat reduced, as the exterior wall at the west end was rebuilt a little further east. Around 1590 the building had increasingly declined into a large barn, with grain storage and wine pressing. In the same period, it acquired embrasures. In 1758, the interior was once more completely changed; newly constructed intermediate floors made it possible to store even more grains. In 1893, the building was restored as far as was possible to its original condition. The intermediate floors were removed and the pointed-arched windows restored to the great hall on the upper floor. Today the hall can be rented for social events. Stapfer House In 1599–1600, a plain two-storey building was added on the southwest side of the castle complex, the Hintere Haus or rear building. It was created by uniting the stable and mill under one roof. In 1705–07, the building was lengthened on the east side to create additional grain storage capacity. From 1822 to 1853, the educational reformer Christian Lippe headed an educational institution at the castle which used advanced teaching principles for the period. In 1893 the granary extension was demolished and replaced by a reconstructed battlement leading to the upper gatehouse. Today the rear building is Stapfer House, named for Philipp Albert Stapfer, a revolutionary and a minister in the Helvetic Republic. Since 1960 it has served as the Events