Tristan da Cunha is the most remote inhabited archipelago in the world. Who discovered it?

Tristan da Cunha lies in the south Atlantic Ocean, 2,816 kilometers (1,750 mi) from the nearest land, South Afric. In 1816 the United Kingdom formally annexed the islands, to ensure that the French would be unable to use the islands as a base for a rescue operation to free Napoleon Bonaparte from his prison in Saint Helena. Today, the main island has a permanent population of 275.