The Cambridge History of India, Vol. III: Turks and Afghans v3.c30.s1.49.2

v3.c30.s1.49.2

In the case of Daulatābād, however, there can be no doubt that though some of its defences were devised by the Yādavas and others by the Bahmanīs or their successors, some also were the work of Muhammad Tughluq at the time (1339) when he transferred the population of Delhi to Daulatābād, and constituting, as this city does, one of the most striking examples of fortification known to the mediaeval world, it rightly deserves special notice. Its inner citadel stands on an isolated conical rock 600 feet in height, with sides scarped sheer for 150 feet and a moat hewn out of the living rock at their base. The only entrance is through a devious tunnel which in times of siege was rendered impassable by an ingenious contrivance. At a bend in the tunnel which came near to the outer edge of the rock was a small chamber provided with a flue pierced through the thickness of the wall and fitted, in addition, with a staging of iron plates. On these plates a charcoal fire was lit which, fanned by the wind blowing incessantly through the flue, would quickly fill the tunnel with its fumes and make any ingress impossible. Round about this almost impregnable acropolis, which, be it added, possesses its own perennial springs of water, was a highly complex system of fortifications designed to protect the city.