THE MAMLUK (SLAVE) DYNASTY (Continued)   Iltutmish (1210 AD - 1236 AD), son-in-law of Aibak - succeeded Aibak as the sultan by defeating Aibak's son. Thus, the principle of heredity, of son succeeding his father was checked at the outset. Iltutmish must be regarded as the real consolidator of the Turkish conquests in north India. He gave the new state capital, Delhi, a monarchical form of government and governing class. He introduced Iqta - grant of revenue from a territory in lieu of salary. He maintained a central army and introduced coins of Tanka (silver) and Jital (copper). The famous Qutub Minar was completed during his reign. He despatched an expedition against the Chalukyas of Gujarat but it was repelled with losses. Around this time, Mongols under the leadership of Ghinghiz Khan, swept across central Asia and mercilessly sacked the kingdoms. They periodically crossed river Indus to attack Punjab and Iltutmish had to keep constant check on this side.   The Qutub Minar