A popular and religious form of Mudéjar art existed alongside the aristocratic and civic version, which is evident in the places of worship used by the people, such as parish churches, convents and monasteries. The religious Mudéjar style brought about the combination of Islamic decorative and structural elements with Romanesque and Gothic styles, examples of which include the use of brick instead of stone as a building material, and wooden instead of vaulted ceilings. Along with these and other general features, the Mudéjar style threw up regional differences determined by the fact that different regions were conquered at different times by the Christian kings.