At the time of the British withdrawal, 565 princely states were officially recognised in the Indian subcontinent,  apart from thousands of regional and local chiefs including taluqars, zamindaris and jagirs. In 1947, princely states numbering 555 covered 48% of area of pre-Independent India and constituted 28% of its population.

The most important states had their own British Political Residencies:

Hyderabad, Mysore and Travancore in the South followed by Jammu & Kashmir and Sikkim in the Himalayas, and Indore in Central India. Gun-salutes were often given for personal distinctions of the ruler rather than the importance of the state and varied from time to time. The most prominent among those – roughly a quarter of the total – had the status of a salute state, one whose ruler was honoured by receiving a set number of gun salutes on ceremonial occasions, ranging from nine to 21. Rulers of salute states entitled to a gun salute of eleven guns and above received from the British the style of His/Her Highness; while the Nizam of Hyderabad had the unique style of His Exalted Highness.

The princely states varied greatly in status, size, and wealth; the premier 21-gun salute states of Hyderabad and Jammu and Kashmir were each over 200,000 km² in size, or slightly larger than the whole of Great Britain. In 1941, Hyderabad had a population of over 16 million,, while Jammu and Kashmir had a population of slightly over 4 million,

comparable to that of Switzerland. At the other end of the scale, the non-salute principality of Lawa covered an area of 49 km²  with a population of just below 3,000. Some two hundred of the lesser states had an area of less than 25 km² (10 mi²).  At the time of Indian independence in 1947, Hyderabad had annual revenues of over Rs. 9 crore (roughly £6.75 million/$27.2 million in 1947 values, approximately £240 million/$290 million in 2014 values), and its own army, airline, telecommunication system, railway, postal system, currency, radio service and a major public university; the tiny state of Lawa had annual revenues of just Rs. 28,000 (£2100/$8463 in 1947 values, £73,360/$89,040 in 2014 values).^[

The era of the princely states effectively ended with Indian independence in 1947. By 1950, almost all of the principalities had acceded to either India or Pakistan. The accession process was largely peaceful, except in the cases of Jammu and Kashmir (whose ruler opted for independence but decided to accede to India following an invasion by Pakistan-based forces), Hyderabad (whose ruler opted for total independence in 1947, followed a year later by the police action and annexation of the state by India), Junagadh (whose ruler acceded to Pakistan, but was annexed by India).^[10] and Kalat (whose ruler opted for independence in 1947, followed in 1948 by the state’s annexation

STAMPS OF PRINCELY INDIAN STATES