he confined the marginal inscription to the obverse. His successor, Qut̤bu-d-dīn Mubārak, whose issues are in some respects the finest of the whole series, employed the old Indian square shape[50] for some of his gold, silver and billon. On his coins appear the even more arrogant titles, “_The supreme head of Islām, the Khalif of the Lord of heaven and earth_.” G̱ẖ̱iyās̤u-d-dīn Tug̱ẖlaq was the first Indian sovereign to use the title _G̱ẖ̱āzī_, “Champion of the faith.” [49] The correct form of the Sultan’s name is Īltutmish; Altamsh is a popular corruption. [50] Two gold coins of ’Alāu-d-dīn Muḥammad are the earliest known Muhammadan coins of this shape. Cf. _Num. Chron._, 1921, p. 345. Among the greatest rarities of this period are the silver tankahs of two _rois fainéants_, Shamsu-d-dīn Kaiyūmars̤, the infant son of Mu’izzu-d-dīn Kaiqubād (1287-1290), and Shihābu-d-dīn ’Umar, brother of Qut̤bu-d-dīn Mubārak, who each occupied the throne only a few months. Most of the coins struck in billon by these early Sultans, including Muḥammad of G̱ẖ̱or, are practically uniform in size and weight (about 56 grains), the difference in value depending upon the proportions in which the two metals were mixed in them. This question has not yet been fully investigated, but it is probable that different denominations were marked by different types.[51] The drawback to such a coinage lay, as already noted, in the impossibility of obtaining uniformity in coins of the same denomination, and in the consequent liability to abuse. Numerous varieties were struck. The Indian type known as the _Dehlīwāla_, with the humped bull and the sovereign’s name in Nāgarī on the reverse, and the Dehlī Chauhan type of horseman on the obverse, lasted till the reign of ’Alāu-d-dīn Mas’ūd (1241-1246); on some coins of this class Altamsh’s name is associated with that of Chāhada-deva of Narwar. Another type, with the Horseman obverse and the Sultan’s name and titles in Arabic on the reverse (Pl. VII, 3), survived till Nāṣiru-d-dīn Maḥmūd’s reign,[52] when it was replaced by coins with a similar reverse, but, on the obverse, the king’s name in Arabic appears in a circle surrounded by his titles in Nāgarī (Pl. VIII, 4). On the commonest type of the later Sultans Arabic legends are in parallel lines on both obverse and reverse. The billon coins of ’Alāu-d-dīn Muḥammad are the first to bear dates. Qut̤bu-d-dīn Mubārak employs a number of special types, including those square in shape (Pl. VIII, 6). Billon coins, mostly of the Bull and Horseman type, were also struck by a number of foreigners who invaded Western India during the thirteenth century. The most important of these was the fugitive king of Ḵẖ̱wārizm Jalālu-d-dīn Mang-barnī. [51] _J.A.S.B._, N.S., XXXV, p. 25. [52] A single specimen is known of the reign of Balban.