St. Olof's Church was originally built around the year 1100 and it consisted of a main tower, chancel and nave. It was later extended, but the construction was probably interrupted when archbishop’s seat was moved to Gamla Uppsala in the 12th century.
St. Olof's church has been influenced by the Nidaros Cathedral in Norway, while the small tapering windows have an Anglo-Saxon style. The church is dedicated to the Norwegian viking Olaf Tryggvasson, king between 995-1000.
It is not certain by whom the church was built. Most probably it was authored by the Benedictines or local trade guild. Archaelogical excavations have revealed remains under the church, which are thought to have belonged to an even older stone church. It may have been one of the first built in Sweden.
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.