St Helena is said to have been first located by the Portuguese in 1502, although there is reason to believe that it may only have been discovered on 30 July 1503 by a squadron under the command of Estavao da Gama.  For over 150 years the island was used by Portuguese, Dutch and English mariners as a victualling station on their return passage from the East Indies.  With the exception of sick sailors and escaped slaves, none of whom remained for any length of time, the island remained uninhabited.  The Dutch formally laid claim to St Helena in 1633 with the intention to fortify it, but this was never followed up.

The island had been a regular port of call for the ships of the London East India Company since 1603, and in 1658 the Company decided to fortify and settle St Helena.  On 5 May 1659 Captain John Dutton landed at the island with 40 men, both soldiers and planters, acting on his instructions that he “repaire on shoare, and in the name of his Highnesse Richard Lord Protector of England Scotland and Ireland and the Dominions thereunto belonging, and for the use of the Honoble English East India Company doe take posession of the Island ...”.  Having thereby acquired its first territorial possession, the East India Company's principal aim was to develop St Helena as a permanent base for supplying its ships on their return voyages from the East Indies, maintaining there large stores of both local and imported produce.  The Company's settlement was recognised in King Charles II's charter of April 1661, which states amongst much else that “it shall and may be lawful to and for the said Governour and Company ... to errect and build such castles Fortifications Forts Garrisons Colonies or Plantations at St Helena ... as they in their directions shall think fit ...  And for the Supplying of such  ... to send out from this Kingdom ... all kind of Cloathing Provision of Victuals Ammunition and Implements necessary ...  As also to Transport and carry over such Number of Men being willing thereunto ...  And also to govern them in such Legal and reasonable manner as the said Governour and Company shall think fit ...”

St Helena was formally granted to the East India Company in 1673 after the Royal Navy had captured the island from the Dutch, who had occupied it from January to May of that year.  The Company's proprietorship of the island continued until April 1834, when St Helena was vested in the Crown by provision of the Government of India Act 1833, although the East India Company continued to administer the island until 1836.  The island has been a colony ever since, although it is now more commonly described as a dependent territory.  Ascension Island, 700 miles to the north west, became a dependency of St Helena in 1922, as did Tristan da Cunha, 1200 miles to the south west, in 1938.