1 Tanka - Muhammad bin Tughluq

Muhammad bin Tughluq's billon tanka issues of this period are inseparable from one of the most audacious monetary experiments in medieval history. Around 1329, he introduced a token currency in copper and brass intended to replace silver — a scheme that collapsed catastrophically when the sultan failed to control counterfeiting and was forced to redeem the debased tokens at face value in silver, reportedly bankrupting the treasury. The billon issues represent the fractured monetary environment surrounding that debacle.

Ibn Battuta, who served at the Delhi court during these years, recorded the chaos firsthand.