Fehtija Mosque is a mosque and former Catholic church located in the town of Bihać, Bosnia and Herzegovina. Built in 1266, it is the oldest gothic building in the country. It was originally built as a Catholic church dedicated to Saint Anthony of Padua, and was subsequently transformed into a mosque following the 1592 conquest of Bihać from Habsburg Croatia by the Ottomans. The building was originally accompanied by a monastery, which was also mentioned in a 13th-century charter of the Croatian nobility.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.