The Indo-Islamic architectural style developed under the Delhi Sultanate and Mughal Empire. Key features included the use of arches, domes, and minarets in mosques and mausoleums. Ornamentation included intricate arabesque patterns and calligraphy without images of living beings. Jali screens regulated light and airflow. The Sultanate era saw three phases of architectural development, with early buildings incorporating materials from demolished Hindu temples. Major structures from this period included the Qutub Minar complex and tombs of Iltutmish and Alauddin Khilji. Provincial styles also emerged as architectural activities decentralized later in the Sultanate.