Medieval Muslim empire covering large portions of present-day India and Pakistan, ruled by a series of five dynasties — the Mamluks (r. 1206–90), Khiljis (r. 1290–1320), Tughlaqs (r. 1320–1413), Sayyids (r. 1414–51) and Lodis (r. 1451–1526), with the city of Delhi as their capital. Its first ruler was Qutubuddin Aibak (r. 1206–10), a Turkish slave and the governor of Lahore and Delhi under the Afghan Muhammad Ghori, though the Delhi Sultanate as a hereditary monarchy was established by his successor Iltutmish (r. 1210–36). It reached its territorial peak under Muhammad bin Tughlaq (r. 1325–51). Over three centuries, the Sultanate witnessed the development of the Hindustani language and Indo-Islamic architecture, as well as the iqta system of revenue collection; but the period was also fraught with political instability and violent succession conflicts. Ibrahim Lodi’s (r. 1517–26) defeat to Babur (r. 1526–30) in 1526 paved the way for Mughal rule.