In 1334 bubonic plague wiped out more than half his army, and the army ceased to be effective. Due to this, in 1334 the Pandyan kingdom (Madurai) rejected the authority of the sultanate and this was followed by Warangal. In 1336 the Vijayanagara empire and in 1337 the Bahamani kingdom were founded. They built magnificent capitals and cities with many splendid buildings, promoted arts and also provided law and order and the development of commerce and handicrafts. Thus while the forces of disintegration gradually triumphed in North India, south India and the Deccan had a long spell of stable government.
Experiments with Coins
Muhammad Bin Tughlaq is known for his active interest in experimenting with the coinage. He implanted his character and activities on his coinage and produced abundant gold coins compared to any of his predecessors. He overtook them by executing a fine calligraphy and by issuing number of fractional denominations. An experiment with his forced currency places him in the rank of one of the greatest moneyers of Indian history though it wasn't successful in India.
The large influx of gold due to his southern Indian campaign made him to adjust the weight standard of coinage which was in usage all the while. He added the gold dinar of weight 202 grains while compared to the then standard weight of 172 grains. The silver adlis weighed 144 grains weight and was his innovation aiming to adjust the commercial value of the metal with respect to gold. Seven years later, he discontinued it due to lack of popularity and acceptance among his subjects.
All his coins reflect a staunch orthodoxy. The coins stuck at both Delhi and Daulatabad, were curious and was issued in memory of his late father. The Kalima appeared in most of his coinage, the title engraved were "The warrior in the cause of God", "The trustier in support of the four Khalifs - Abubakkar, Umar, Usman and Ali". He minted coins in several places such as Delhi, Lakhnauti, Salgaun, Darul-I-Islam, Sultanpur (Warrangal), Tughlaqpur (Tirhut), Daulatabad(Devagiri), Mulk-I-Tilang etc., More than thirty varieties of billon coins are known so far, and the types shows his numismatic interest. The copper coins are not that fascinating compared to the billon and his gold coinage, but were minted in varieties of fabric.
Most wonderful of his coinage is the forced currency. He had two scalable versions, issued in Delhi and Daulatabad. They obeyed two different standards, probably to satisfy the local standard pre-existed in north and the south. Sultan's skill in forcing the currency is remarkable. He engraved "He who obeys the Sultan obeys the compassionate" to fascinate people to accept the new media. Inscriptions were even engraved in Nagari legend, but because of the metal which is made, the coinage doomed. The easily forgeable Copper/Brass coinage turned every Hindu house into a mint and soon Sultan withdrew forged currency by paying in Billon and gold!!!