of earlier Indian architecture, such as the use of a high plinth, and often mouldings around its edges, as well as columns and brackets and hypostyle halls. After the death of Firoz the Tughlaqs declined, and the following Delhi dynasties were weak. Most of the monumental buildings constructed were tombs, although the impressive Lodi Gardens in Delhi (adorned with fountains, charbagh gardens, ponds, tombs and mosques) were constructed by the late Lodi dynasty. The architecture of other regional Muslim states was often more impressive. Pre-Mughal regional architecture Significant regional styles developed in the independent sultanates formed when the Tughlaq empire weakened in the mid-14th century, and lasted until most were absorbed into the Mughal Empire in the 16th century. The sultanates of the Deccan Plateau, Gujarat, Bengal and Kashmir are discussed below. The architecture of the Malwa and Jaunpur sultanates has also left some significant buildings. Deccan sultanates The Bahmani Sultanate in the Deccan broke away from the Tughlaqs in 1347, and ruled from Gulbarga, Karnataka and then Bidar until overrun by the Mughals in 1527. The main mosque (1367) in the large Gulbarga Fort or citadel is unusual in having no courtyard. There are a total of 75 domes, all small and shallow and small except for a large one above the mihrab and four lesser ones at the corners. The large interior has a central hypostyle space, and wide aisles with "transverse" arches springing from unusually low down (illustrated). This distinctive feature is found in other Bahmanid buildings, and probably reflects Iranian influence, which is seen in other features such as a four-iwan plan and glazed tiles, some actually imported from Iran, used elsewhere. The architect of the mosque is said to have been Persian. Some later Bahminid royal tombs are double, with two units of the usual rectangle-with-dome form combined, one for the ruler and the other for his family, as at the Haft Dombad ("Seven Domes") group of royal tombs outside Gulbarga. The Mahmud Gawan Madrasa (begun 1460s) is a large ruined madrasa "of wholly Iranian design" in Bidar founded by a chief minister, with parts decorated in glazed tiles imported by sea from Iran. Outside the city the Ashtur tombs are a group of eight large domed royal tombs. These have domes which are slightly pulled in at the base, predating the onion domes of Mughal architecture. The Qutb Shahi dynasty of Hyderabad, not absorbed