Muhammad bin Tughluq The Sultan of Delhi, Muhammad bin Tughluq, issued token currency; that is coins of brass and copper were minted whose value was equal to that of gold and silver coins. Historian Ziauddin Barani felt that this step was taken by Tughluq as he wanted to annex all the inhabited areas of the world for which a treasury was required to pay the army. Barani had also written that the sultan's treasury had been exhausted by his action of giving rewards and gifts in gold. This experiment failed, because, as said by Barani, "the house of every Hindu became a mint". During his time, most of the Hindu citizens were goldsmiths and hence they knew how to make coins. In the rural areas, officials like the muqaddams paid the revenue in brass and copper coins and also used the same coins to purchase arms and horses. As a result, the value of coins decreased and, as said by Satish Chandra, the coins became "as worthless as stones". Vijayanagara Empire (c. 1336–1646 CE) The standard coin issued by the Vijayanagara Empire was the gold Pagoda or Varaha of 3.4 g. The Varaha was also called the Hon, Gadyana or a Pon and came in the Ghattivaraha, Doddavaraha and Suddhavaraha coin. In the gold issue, the different coins came in Varaha, this is used as a reference for the other coins values. There were also other units of silver and copper based on their relationship with the Pagodagold. Several gold ramatankas (token coins), feature the scene of Rama's incoronation, were also issued in the Vijayanagara Empire. Early Mughal Emperors (c. 1526–1540 CE) The Mughal Emperor Babur issued standard Timurid currency coins known as the shahrukhi, named after Shahrukh Mirza, Timur's eldest son. The Shahrukhis were essentially thin broad-flanned coins imprinted with the Sunni kalima or credo on its obverse at the center with the names of the first four caliphs around it. The reverse had the king's name and titles along with the date in the Hijri era and the name of the minting town. Babur's successor Humayun continued the minting of Shahrukhi-styled coins. Sur Empire (c. 1540–1556 CE) The system of tri-metalism which came to characterize Mughal coinage was introduced by Sher Shah Suri. While the term rūpya had previously been used as a generic term for any silver coin, during his rule the term rūpee came to be