At the time of India's Independence there were some 560 Princely States of which 58 maintained armed forces to a standard fit for use in the defence of India if needed. These States chose to join the Imperial Service Troops (IST) scheme, established in the late 1880s and which lasted until 1920; and then the Indian State Forces (ISF) scheme which took over in 1920 and continued through to 1947. A number of other States maintained local forces outside of the two schemes and these are not included here except for a few entries in the last chapter. The contribution made by the IST/ISF troops was important and of great value in the First and Second World Wars, which were covered by the two schemes. They also played a part in earlier campaigns on the North West Frontier and, uniquely, in the Third China War of 1900. These were special arrangements because all the States had separate treaties (sanads) with the Government of Imperial India and these recognized their status in charge of their own internal affairs and their own revenue. These treaties laid no legal obligation to provide troops to serve outside their own State. Thus the IST/ISF schemes created a back-up, at minimum cost, for the Defence of India. The chapters covering the States are set out in alphabetical order. Each covers the background of their antecedent forces where this is known. They also cover the Subsidiary and Contingent Forces provided by the States. Each entry shows the descendant units (where such exist) in the Armies of India and Pakistan. There is also much information on battle and campaign honours, honours and awards won by members of these Forces, as well as notes on uniforms and insignia. This work will become the primary source of reference for the future. Despite the immense amount of research undertaken by the authors there is still work to be done, however, as there are frequent not known' or not listed' entries, a number of anomalies noted, and unidentified items of insignia illustrated. The authors hope that the publication of their work will stimulate the recovery of yet more information.