Belváros (Inner City) Church is the oldest building in Pest side of river in Budapest. It was built in 1046 as a grave of Bishop St. Gellért (c. 980-1046), a missionary from Italy who played an instrumental role in converting Hungary to Christianity. According to tradition, he was martyred by angry pagans who rolled him down a hill across the river, which was named Gellért Hill in his honor.
The first church constructed on this spot was a 12th-century Romanesque structure built inside the ruined walls of the Roman fortress of Contra-Aquincum. In the early 14th century, after destroyed by Mongols, this church was replaced by a Gothic church which still stands today. It has been frequently renovated and remodeled in accordance with contemporary fashions, so its medieval origins are not obvious at first glance.
During the reign of Ottoman Empire Belváros was used as a mosque and in 1702 it was returned as a Christian church by Jesuits. The Rococo style pulpit dates from 1808.
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.