The prosperity of the country was due in a considerable measure to the extension of agriculture by reclaiming virgin lands and making new settlements on them. Before the coming of the Muslims vast tracts of alluvial lands, especially in the southern regions, were still covered forests. The attention of the new comers was directed to the reclamation of these lands partly for the purpose of settling immigrants who poured into the country from time to time, and partly for increasing its agricultural out – put by bringing more of those fertile tracts under cultivation.  The work seems to have been undertaken quite early in the period, though the exact time and the areas involved are not known, for its salutary effects were observed in the first half of the fourteenth century. A Chinese account of 1349-50 states: “These people owe all their tranquillity and prosperity to themselves, for its source lies in their devotion to agriculture whereby a land originally covered with jungle has been reclaimed by their unremitting toil in tilling and planting. [Source: History of The Muslims of Bengal Vol 1B pages  931-932 Publisher: Imam Muhammad Bin Sa’ud University. First Edition 1406H/1985]