The ruins of the former Biskopsborgen fort can be seen on the skyline a few hundred metres west of Husaby church. Its name means the Bishop’s Fort and it was built for the Bishop of Skara. The fort consists of an imposing tower and a surrounding stone ring wall with adjoining smaller buildings in timber and brick. Medieval sources do not give a fixed date for the building but it is most likely that it was built in about 1480. However, the fort was not in use for very long. After the Västerås Riksdag of 1527, which severed Sweden’s ties with the Roman Catholic Church, the fort was seized by the Crown and it is likely that it was intentionally burned and razed to the ground as King Gustav Vasa was unwilling to tolerate any competition against the power of the Crown in Sweden.
The fort underwent several phases of construction. The central tower was built first, followed by another building beside it known as “kasematten”, along with parts of the row of buildings bordering the eastern courtyard, after which the ring wall may have been completed. Excavations found a huge number of finds – a hand cannon with an octagonal pipe and a hook underneath to protect the firer from the recoil dating from the fourteenth century, several guns and arrowheads, spearheads, swords, stone cannonballs, parts of armour and axes, including a “bearded axe”. There were also picks, drills and a ploughshare plus knives, chisels, scissors and tongs, but very few ceramics. The lower part of the fort is partly preserved.