"The reign of Ahmad I, which did much to consolidate the new Sultanate, lasted thirty-three years, much of which was occupied in warfare against neighbouring Rajput princes and his Muslim neighbours of Malwa, Khandesh, and the northern Deccan. In the year of his accession he had founded the capital city which still bears his name, Ahmadabad, on the left bank of the Sabarmati, with a citadel and spacious streets. He soon moved against Junagadh, compelling the payment of tribute, and from this time extended the power of the Sultanate into the central region of Saurashtra as well as the coastal lands already in Sultanate control; he also exacted tribute from the Hindu raja of Champaner. The Hindu state of Idar was a source of perpetual trouble, and Ahmad built the city of Anmadnagar (renamed Himatnagar in the twentieth century) some thirty kilometres south of Idar as a base of operations. Idar submitted on the death of the raja, although intermittent warfare with Gujarat continued for several generations thereafter. The Bahmani sultan sent a force to capture the then island of Mahim (now a part of Bombay) which was under Gujarat suzerainty in 1431, but Ahmad’s generals forced the capitulation of Thana, the Bahmanis’ most important town of the northern Konkan coast, and then recovered Mahim from the invader. In his last major campaign against his Hindu neighbours, in 1432-38, he overcame the ruler of Pavagadh and Champaner, sacked Nandod, and even forced tribute from the rulers of the distant Dungarpur, Kota and Bundi. He died in 1442 after a reign devoted to consolidating Islam in his dominions by relentless iconoclasm and oppression of the Hindus. His justice was strict but impartial, and he was known for his piety and as a disciple of two great religious teachers, Shaikh Ahmad Khattu of Sarkhej and Burhanuddin Qutb-i Alam of Vatva."