Conversion of places of worship Main article: Conversion of non-Muslim places of worship into mosques

The Umayyad Mosque in Damascus, Syria was a Byzantine church before the Islamic conquest of the Levant. Some ecclesiastical elements are still evident.

According to early Muslim historians, towns that surrendered without resistance and made treaties with the Muslims gave the Muslims permission to take their churches and synagogues, One of the earliest examples of these kinds of conversions was in Damascus, Syria, where in 705 Umayyad caliph Al-Walid I bought the church of St. John from the Christians and had it rebuilt as a mosque in exchange for building a number of new churches for the Christians in Damascus, overall, Abd al-Malik (Al-Waleed's father) is said to have transformed 10 churches in Damascus into mosques.

The process of turning churches into mosques was especially intensive in the villages where most of the inhabitants converted to Islam. The Abbasid caliph al-Ma'mun turned many churches into mosques. Ottoman Turks converted nearly all churches, monasteries, and chapels in Constantinople, including the famous Hagia Sophia, immediately after capturing the city in 1453 into mosques. In some instances mosques have been established on the places of Jewish or Christian sanctuaries associated with Biblical personalities who were also recognized by Islam.^[13] Buddhist, Jain & Hindu temples of the Indian subcontinent were also converted forcibly into mosques during the Islamic rule of India, which Jains, Hindus want to reclaim in modern times, leading to communal conflicts.

Mosques have also been converted for use by other religions, notably in southern Spain, following the conquest of the Moors in 1492.^[14] The most prominent of them is the Great Mosque of Cordoba. The Iberian Peninsula & Southeast Europe are other regions in the world where such instances occurred once no longer under Muslim rule.