St. Walfridus kerk was founded ca. 1050. Bedum became a place of pilgrimage because of the graves of martyrs Walfridus and Radfridus. Two churches were built, originally in wood. Nothing remains of the chapel of Radfridus, and the St. Walfridus church did not survive in good state either due to a downturn in pilgrimages after the 16th century.
In ca. 1050 work started on a three-aisled cruciform basilica in Romanesque style, which was completed in the 12th century. Of this church only the tower remains. Traces of arches indicate that this tower originally was part of a reduced westwork, with spaces flanking the tower on both sides. These were demolished soon after. The tower leans forward, more than any other tower in the country. It is argued that the tower leans more than the Leaning Tower of Pisa, due to restoration at the latter site.
Of the original nave only a few pillars and a small piece of wall have survived. In ca. 1484 the church was enlarged into a two-aisled hall-church. The southern side-aisle was replaced by a new one in Gothic style which was of the same height and width as the nave. The southern transept-arm was renewed in the same style and completely integrated in the side-aisle. On the northern side either a lower side-aisle or a series of chapels was added. An incomplete transept-arm is still recognizable. In the first decades of the 16th century a new Gothic choir with an ambulatory was built, fit for the church's use by a chapter, which was demolished by the Protestants in ca. 1600. In about the same period the walls of the northern transept-arm were lowered and partly rebuilt. Later the complete northern wall was renewed.
The sagging of the tower has been a problem for a long time. In the 17th century buttresses were added, which already needed replacing in ca. 1800 and were again demolished in the 1850s. During a restoration in 1953-1958 a more perment solution was found by adding an underground counter-weight. The same restoration resulted in the lozenge roof of the tower, which replaced a flat roof that had covered the tower ever since a fire destroyed the spire in 1911.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.