Conversion of non-Islamic places of worship into mosques
The conversion of non-Islamic places of worship into mosques occurred during the life of Muhammad and continued during subsequent Islamic conquests and invasions and under historical Muslim rule. Hindu temples, Jain Temples, Christian churches, synagogues, and Zoroastrian fire temples have been converted into mosques. Several such mosques in the areas of former Muslim rule have since been reconverted or have become museums, including the Parthenon in Greece and numerous mosques in Spain, such as Mosque–Cathedral of Córdoba, etc. Conversion of non-Islamic buildings into mosques influenced distinctive regional styles  of Islamic architecture. Qur'anic holy sites. Mecca. Before Muhammad, the Kaʿba and Mecca (referred to as Bakkah in the Quran), were revered as a sacred sanctuary and was a site of pilgrimage. At the time of Muhammad (AD 570–632), his tribe the Quraysh was in charge of the Kaʿaba, which was at that time a shrine containing hundreds of idols representing Arabian tribal gods and other religious figures. Muhammad earned the enmity of his tribe by preaching the new religion of Islam. Early Muslims practiced, or attempted to practice, their rituals by the Ka'aba alongside polytheists, until they eventually left  Mecca, driven out by escalating persecution. The aborted first pilgrimage, which was prevented by the Quraysh, who promised to allow it the following year in the Hudaybiyah treaty, did not also entail the prevention of continuing practices by polytheists. However, before the second pilgrimage season, allies of the Quraysh violated the treaty, allowing the Muslims to return as conquerors rather than guests. Henceforth, the Kaʿaba was to be dedicated to the worship of the one God alone, and the idols were destroyed. The Black Stone (al-Hajar-ul-Aswad) at the Kaʿaba was a special object of veneration at the  site. According to some traditions the text of seven or ten especially honoured poems were suspended around the Kaʿaba. Jerusalem. Upon the capture of Jerusalem, it is commonly reported that Umar, the Commander of the Faithful, refused to pray in the Church of the Holy Sepulchre in spite of a treaty. The architecturally similar Dome of the Rock was built on the Temple Mount, which was an abandoned and disused area since 70 AD in the 7th century but which had previously been the site of the Jewish Temple in Jerusalem, the most sacred site in Judaism. Umar initially built  there a small prayer house which laid the foundation for the later construction of the Al-Aqsa mosque by the Umayyads. Elsewhere. The mosque of Job in Al-Shaykh Saad, Syria, was previously a church of Job. The Ummayad Mosque in Syria once the cathedral of St. John the Baptist where the mortal remains of John the Baptist are interrred was converted to a mosque during the islamic persecution in the caliphate. The Herodian shrine of the Cave of the Patriarchs in Hebron, the second most holy site in Judaism, was converted into a church during the Crusades before being  turned into a mosque in 1266 and henceforth banned to Jews and Christians. Part of it was restored as a synagogue by Israel after 1967. Other sites in Hebron have undergone Islamification. The Tomb of Jesse and Ruth became the Church of the Forty Martyrs, which then became the Tomb of Isai and later Deir Al Arba'een. Conversion of Hindu Temples into Mosques. As described by Jadunath Sarkar, on 9 April 1669, Aurangzeb issued a general order “to demolish all the schools and temples of the infidels and to put down their religious teaching and practices.” His destroying hand now  fell on the great shrines that commanded the veneration of the Hindus all over India—such as the second temple of Somnath, the Vishwanath temple of Benares and the Keshav Rai temple of Mathura. Zoroastrian fire temples. After the Islamic conquest of Persia, Zoroastrian fire temples, with their four axial arch openings, were usually turned into mosques simply by setting a "mihrab" (prayer niche) on the place of the arch nearest to "qibla" (the direction of Mecca). This practice is described by numerous Muslim sources; however, the archaeological evidence confirming it is still scarce. Zoroastrian temples converted into mosques in  such a manner could be found in Bukhara, as well as in and near Istakhr and other Iranian cities, such as: Tarikhaneh Temple, Jameh Mosque of Qazvin, Heidarieh Mosque of Qazvin, Jameh Mosque of Isfahan, Jameh Mosque of Kashan, Jameh Mosque of Ardestan, Jameh Mosque of Yazd, Jameh Mosque of Borujerd, Great Mosque of Herat as well as Bibi Shahr Banu Shrine near Tehran. Conversion of church buildings to mosques. Bosnia and Herzegovina. The Fethija Mosque (since 1592) of Bihać was a Catholic church devoted to Saint Anthony of Padua (1266). Turkey. Before the 20th century. Istanbul. Following the Ottoman  conquest of Anatolia, virtually all of the churches of Istanbul were converted into mosques except the Church of St. Mary of the Mongols. Rest of Turkey. Elsewhere in Turkey numerous churches were converted into mosques, including: Armenian Apostolic. Hundreds of Armenian Churches were converted into Mosques in Turkey and Azerbaijan. Thousands were destroyed after Armenian Genocide in 1915 20th century and after. In addition, after the Greco-Turkish War (1919–1922), some of the Greek Orthodox churches in Turkey were converted into mosques. In 2015, Turkey decided to renovate the ruined Hagia Sophia church in Enez, dating back to the 12th  century, as a mosque despite former statements made about the possibility of restoring it as a museum. As of 2020, four Byzantine church museums converted to mosques under Erdogan's rule (including the Haghia Sophia in İznik (2011), the Chora Church in Istanbul (2019) and the Haghia Sophia in Istanbul (2020)). Cyprus. Following the Ottoman conquest of Cyprus, a number of Christian churches were converted into mosques. A relatively significant surge in church-mosque conversion followed the 1974 Turkish Invasion of Cyprus. Many of the Orthodox churches in Northern Cyprus have been converted, and many are still in the process  of becoming mosques. France. During the Ottoman wintering in Toulon (1543–44), the Toulon Cathedral was temporarily used as a mosque for the 30,000 members of the crew of the Ottoman fleet. Greece. Numerous orthodox churches were converted to mosques during the Ottoman period in Greece. Among them: Crimea. After the Ottomans conquered Mangup, the capital of Principality of Theodoro, a prayer for the Sultan recited in one of the churches which converted into a mosque, and according to Turkish authors "the house of the infidel became the house of Islam." Hungary. Following the Ottoman conquest of the Kingdom of Hungary , a number of Christian churches were converted into mosques. Those that survived the era of Ottoman rule, were later reconverted into churches after the Great Turkish War. Spain. A Catholic Christian church dedicated to Saint Vincent of Lérins, was built by the Visigoths in Córdoba; during the reign of Abd al-Rahman I, it was converted into a mosque. In the time of the Reconquista, Christian rule was reestablished and the building became a church once again, the Cathedral of Our Lady of the Assumption. Post-colonial North Africa. A number of North African cathedrals and churches were converted into  mosques in the mid-20th century Iraq. The Islamic State of Iraq and Syria converted a number of Christian churches into mosques after they occupied Mosul in 2014. The churches were restored into its original functions after Mosul was liberated in 2017. Influence on Islamic architecture. Conversion of non-Islamic religious buildings into mosques during the first centuries of Islam played a major role in the development of Islamic architectural styles. Distinct regional styles of mosque design, which have come to be known by such names as Arab, Persian, Andalusian, and others, commonly reflected the external and internal stylistic elements of  churches and other temples characteristic for that region.