The Arab Mosque is Istanbul's largest transformed mosque. Also, it is the largest mosque of the Galata neighbourhood. It is the only endured, Gothic-Italian style architecture from the pre-conquest era. However, there are disagreements among historians about whether the mosque was built as a mosque originally. Although there aren't many clues supporting the architecture was originally a mosque, some claim that the architecture was built by the orders of Emevi Commander, Mesleme bin Abdülmelik, during the Emevi Blockade of constantinople in the year 717. According to another rumour, the Arab Mosque was the first mosque where the first sounds of the call to prayer swelled towards sky. Nevertheless, it can be understood that the mosque was originally a church because the first mosque in Istanbul, which was built by the permission of Byzantine Empire for the muslim public, was located inside the walled city. The church was most likely built upon the remains of the Hagia Eirene under the Latin authority during the 6th century. Since then, the members of the Dominican sectarian took the possession of the church and built a large monastery and a new church in the names of St. Paolo and St. Domenico, instead of the original church built during the Latin authority. Within the 14th century and the first half of the 15th century, a great number of Italians were buried in this new church.
After the conquest of Istanbul, mehmed the Second (also known as mehmed the Conqueror) personally ordered the transformation of the church into a mosque. This new mosque is mentioned in the foundation-certificate-charters as the Galata Mosque. However, Arab Muslims who migrated from Spain in the 15th century have settled in the Galata neighbourhood, especially near the Galata Mosque. Subsequently, the Galata Mosque was colloquially mentioned as the Arab Mosque. The originality of the architecture of the mosque sources from these rumours. As Arabs have lived in the Galata neighbourhood since the 15th century, the public thought that the mosque was originally built by the Arabs during the Emevi Blockade of constantinople. In addition, the bell tower of the architecture has a similar resemblance to the minaret of the Emevi Mosque in Damascus, which has also supported the rumours.
During the 17th century, the Arab Mosque was restored under the reign of sultan Mehmed the 3rd, and the buildings that surrounded the mosque were demolished under the orders of the sultan. In addition to Sultan Mehmed the 3rd, Safiha Sultan (mother of Sultan Mahmud the 1st) and Adile Sultan (daughter of Sultan Mahmud the 2nd) ordered the restoration of the mosque at different times in history. During the period of Adile Sultan, the public fountain, the drinking fountain and ablution fountain were built. Additionally, the wooden interior and gathering-places of the Arab Mosque were changed into a baroque style during the period of Saliha Sultan. A theatric appearance dominated the interior design after these changes. Between the years 1913 and 1919, the Arab Mosque was restored once again and went through big changes. The walls of the yard were completely pulled down and the mosque was reconstructed and expanded. During the last restoration, tombstones of over a hundred Latin nobles under the slab bottom were moved to a museum. Although the architecture was pretty much Islamized, any careful observer can distinguish the gothic past of the architecture.