(pre-stamp postal history here)
The usage of the stamps began on 1 July 1852 in Scinde district, with the use of an embossed pattern on paper or wax. The shape was circular, with "SCINDE DISTRICT DAWK" around the rim, leading to the common name "Scinde Dawk". The paper was either white or blue, and the wax version on red wax, but all had the same value of 1/2 anna. They were used until October 1854, and then officially suppressed. These are quite scarce today, with prices from US$700 to $10,000.
1854 was the year of the first issue for all of India. The stamps were issued by the East India Company, which first printed a 1/2a vermilion in April but never sold it to the public, then put four values (1/2a, 1a, 2a, 4a) on sale in October. All were designed and printed in Calcutta, featuring the usual profile of Queen Victoria.
A new set of stamps, with the queen in an oval vignette inside a rectangular frame, and inscribed "EAST INDIA POSTAGE", was printed by De La Rue in England (who produced all the subsequent issues of British India) and made available in 1855. These continued in use until after the British government took over administration of India in 1858, and from 1865 were printed on paper watermarked with an elephant head.
In 1866 new designs for 4a and 6a8p stamps were issued, but 6a stamps were improvised but cutting the tops and bottoms from revenue stamps, and overprinting "POSTAGE". Another four new designs appeared one at a time between 1874 and 1876.
A complete new set of stamps was issued in 1882 for the Empire of India that had been proclaimed in 1877. The designs consisted of the usual Victoria profile, in a variety of frames, inscribed "INDIA POSTAGE". The watermark also changed to a star shape. These stamps were heavily used and are still quite common today, the lower denominations selling for minimal prices in used form. (In fact, almost all stamps of India from this point exist in great numbers.)
High values - 2, 3 and 5 rupees were introduced in 1895, and in 1900 existing designs were reprinted in new colors.
In 1902 a new series depicting King Edward VII generally reused the frames of the Victoria stamps, with some color changes, and included values up to 25 rupees.
The 1911 stamps of King George V were more florid in their design. In 1919 a 1 1/2 anna stamp was introduced, inscribed "ONE AND HALF ANNA", but in 1921 this changed to "ONE AND A HALF ANNAS". In 1926 the watermark changed to a pattern of multiple stars.
The first pictorial stamps appeared in 1931. The set of six, showing the fortress of Purana Qila and government edifices, was issued to mark the government's move from Calcutta to New Delhi. Another pictorial set, also showing buildings, commemorated George's Silver Jubilee in 1935.
Higher-value stamps of the King George VI issue of 1937 depicted forms of mail transports. A new issue in 1941, constrained by the demands of the war, consisted of rather plain designs using minimal amounts of ink.
A victory issue in 1946 was shortly followed by a first Dominion issue, whose three stamps were the first to depict the Asoka Pillar and the national flag of India (the third showed an airplane).
A memorial to Mahatma Gandhi was issued 15 August 1948, and followed up exactly one year later by a definitive series depicting cultural heritage, mostly Hindu temples and gods.
An issue on 26 January 1950 commemorated the inauguration of the Republic.
Definitives included a technology and development theme in 1955, a series all showing the same map of India in 1957, denominated in naye paisa (decimal currency), and a series with a broad variety of images in 1965.
The modern stamps of India are not especially popular with collectors; the designs are often dull and the printing of low quality. They are interesting for the large number of gurus and holy men depicted.