The study of fortification in the Indian subcontinent is a discipline not only of intrinsic merit but also of considerable extrinsic value, for the material it may be expected to yield is of relevance to the archæologist, antiquarian, and historian, taking these terms in the broadest sense; indeed, it is these, in somewhat narrower terms perhaps, who have helped to amass the not inconsiderable body of material which is at present available on the fortified sites in the subcontinent, most of which have long been known to archæologists and art-historians. The old series of Archæological Survey of India Reports (1862–84), largely reports of tours by Cunningham and his associates, contain much material on the major fortified sites of the subcontinent, although some of this is merely incidental to the main purposes of the reports; the New Imperial Series of the Archæological Survey, including the regional surveys, presents more precise and detailed description of individual sites, and this is supplemented by the Archæological Survey of India Annual Reports, from 1902 onwards, and the reports of various states with autonomous departments of archæology, most notably the Nizām's Dominions whose sometime Director, Dr. Ghulam Yazdani, has in addition to considerable work on the Deccan sites published in those reports produced two valuable monographs. These works have supplemented the evidence of the sites themselves with the available historical material, documentary and epigraphic, and further epigraphic material is available in the volumes of Epigraphia indica and Epigraphia indo-moslemica, as well as in some of the Memoirs of the A.S.I. Less reliable technically, but always useful and often suggestive, is the information available in the gazetteers of the various provincial governments and states. The journals of learned societies with an Indian interest add more to this material, as do the catalogues and journals of Indian museums.