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 Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.