The islands in the group have been declared Special Nature Reserves under the South African Environmental Management: Protected Areas Act, No.

Barent Barentszoon Lam of the Dutch East India Company reached the islands on 4 March 1663 on the ship Maerseveen.

They were named Dina (Prince Edward) and Maerseveen (Marion),[10] but the islands were erroneously recorded to be at 41° South, and neither were found again by subsequent Dutch sailors.

[11][12] In January 1772, the French frigate Le Mascarin, captained by Marc-Joseph Marion du Fresne, visited the islands and spent five days trying to land, thinking they had found Antarctica (then not yet proven to exist).

[14] Crozet shared the charts of his ill-fated expedition, and as Cook sailed from Cape Town, he passed the islands on 13 December, but was unable to attempt a landing due to bad weather.

[15] Another landing in late 1803 by a group of seal hunters led by American captain Henry Fanning of the Catharine found signs of earlier human occupation.

[15] The first scientific expedition to the islands was led by James Clark Ross, who visited in 1840 during his exploration of the Antarctic, but was unable to land.

In June 1849 the brig Richard Dart, with a troop of Royal Engineers under Lt. James Liddell, was wrecked on Prince Edward Island; only 10 of the 63 on board survived to be rescued by elephant seal hunters from Cape Town.

[20] In 1908 the Norwegian vessel Solglimt was shipwrecked on Marion Island, and survivors established a short-lived village at the north coast, before being rescued.

[33] In 2018, another cosmology experiment was launched by the McGill team called Array of Long Baseline Antennas for Taking Radio Observation from Sub-Antarctic (ALBATROS).

The new experiment aims to create very high-resolution maps of the low-frequency radio emission from the universe, and take first steps towards detecting the cosmological Dark Ages.

Summer and winter have fairly similar climates with cold winds and threat of snow or frost at any time of the year.

Because of the paucity of land masses in the Southern Ocean, the islands host a wide variety of species and are critical to conservation.

[9] In the cold subantarctic climate, plants are mainly limited to grasses, mosses, and kelp, while lichens are the most visible fungi.

The main indigenous animals are insects (such as the seaweed-eating weevil Palirhoeus eatoni) along with large populations of seabirds, seals[44] and penguins.

[45] The islands have been designated an Important Bird Area (IBA) by BirdLife International for their significant seabird breeding populations.

[49] Currently, the greatest ecological threat is the longline fishing of Patagonian toothfish, which endangers a number of seabirds that dive into the water after baited hooks.

House mice arrived to Marion Island with whaling and sealing ships in the 1800s and quickly multiplied, so much so that in 1949, five domestic cats were brought to the research base to deal with them.

[51] In 2003, ornithologists discovered that in the absence of other food sources, the mice were attacking albatross chicks and eating them alive as they sat helplessly on their nests.

[51] An assessment of the island was completed in May 2015, led by noted invasive species ecologist John Parkes, with the general conclusion that an eradication programme is feasible, but will require precise planning.

[16] On 1 October 1948 the annexation was made official when Governor-General Gideon Brand van Zyl signed the Prince Edward Islands Act, 1948.