Doab

   The fertile region between the Yamuna and Ganges Rivers was generally termed Doab in the early histories of Delhi sul-tanate. To them, Doab and Awadh together represented the Hin-dustan of the 13th and 14th centuries. Most of the Doab was khal-isah during 'Ala al-Din Khalji's reign (1296-1316). Ziya' Barani in this context refers to "the towns (qasbat) of Doab," which indi-cates that by then the number of small urban centers was quite large in the Doab. The revenue collection from the Doab in the late 1360s is calculated at 8,000,000 tankas. As early as Balban's time (1266-1286), the iqta's of the troops of the central army were con-centrated in the Doab. The Doab supplied grain to Delhi. In 1332-1334, the failure of grain supply from the Doab led to a se-vere famine at Delhi that was partly a consequence of local upris-ings. These uprisings led to Muhammad bin Tughlaq's campaigns in Baran, Kol, Qanauj, and Dalmau.