On 14 August 1816, the United Kingdom annexed the islands, making them a dependency of the Cape Colony in South Africa. This was explained as a measure to prevent the islands’ use as a base for any attempt to free Napoleon Bonaparte from his prison on Saint Helena. The occupation also prevented the United States from using Tristan da Cunha as a base for naval cruisers, as it had during the War of 1812. Possession was abandoned in November 1817, although some members of the garrison, notably William Glass, stayed and formed the nucleus of a permanent population.
The islands were occupied by a garrison of British Marines, and a civilian population gradually grew. Berwick stopped there on 25 March 1824 and reported that it had a population of twenty-two men and three women. The barque South Australia stayed there on 18–20 February 1836 when a certain Glass was Governor, as reported in a chapter on the island by W. H. Leigh.
Whalers set up bases on the islands for operations in the Southern Atlantic. However, the opening of the Suez Canal in 1869, together with the gradual transition from sailing ships to coal-fired steam ships, increased the isolation of the islands, which were no longer needed as a stopping port for lengthy sail voyages, or for shelter for journeys from Europe to East Asia. A parson arrived in February 1851, the Bishop of Cape Town visited in March 1856 and the island was included within the diocese of Cape Town.
In 1867, Prince Alfred, Duke of Edinburgh and second son of Queen Victoria, visited the islands. The main settlement, Edinburgh of the Seven Seas, was named in honor of his visit. On 15 October 1873, the Royal Navy scientific survey vessel HMS Challenger docked at Tristan to conduct geographic and zoological surveys on Tristan, Inaccessible Island and the Nightingale Islands. In his log, Captain George Nares recorded a total of fifteen families and eighty-six individuals living on the island. Tristan became a dependency of the British Crown in October 1875.
On November 27, 1885, the island suffered one of its worst tragedies after an iron barque named West Riding approached the island, whilst en route to Sydney, Australia from Bristol. Due to the loss of regular trading opportunities, almost all of the island’s able-bodied men approached the ship in a lifeboat attempting to exchange with the passing vessel. The boat, recently donated by the British government, sailed despite rough waters and, although the lifeboat was spotted sailing alongside the ship for some time, it never returned. Various reports were given following the event, with rumors ranging from the men drowning, to reports of them being taken to Australia and sold as slaves. In total, 15 men were lost, leaving behind an island of widows. A plaque at St. Mary’s Church commemorates the lost men.
20th Century:
After years of hardship since the 1880s and an especially difficult winter in 1906, the British government offered to evacuate the island in 1907. The Tristanians held a meeting and decided to refuse, despite the crown’s warning that it could not promise further help in the future. No ships called at the islands from 1909 until 1919, when HMS Yarmouth finally stopped to inform the islanders of the outcome of World War I. The Shackleton–Rowett Expedition stopped in Tristan for five days in May 1922, collecting geological and botanical samples before returning to Cape Town. Among the few ships that visited in the coming years were the RMS Asturias, a Royal Mail Steam Packet Company passenger liner, in 1927, and the ocean liners RMS Empress of France in 1928, RMS Duchess of Atholl in 1929, and RMS Empress of Australia in 1935. In 1936, The Daily Telegraph of London reported the population of the island was 167 people, with 185 cattle and 42 horses.