[3] It has an area of 142 square kilometres (55 sq mi) (including offshore islets) and a population of 7,324 at the 2012 Census;[4] the latest official estimate (at May 2018) was 8,420.
[5] The island is the main constituent of the Autonomous Region of Príncipe, established in 1995, and of the coterminous district of Pagué.
The island was uninhabited when discovered by the Portuguese on 17 January 1471 and was first named after Saint Anthony ("Ilha de Santo Antão").
[6] Subsequently, the north and centre of the island were made into plantations by Portuguese colonists using slave labor.
[8] Príncipe was the site where Einstein's theory of relativity was experimentally corroborated by Arthur Stanley Eddington and his team during the total solar eclipse of May 29, 1919; photographs of the eclipse revealed evidence of the bending of starlight, in accordance with Einstein's predictions (see Eddington experiment).
[9] Príncipe has one town, Santo António, and an airport (IATA code: PCP, ICAO: FPPR).
In 1875, the year when slavery was officially abolished in the archipelago, Príncipe's population had dropped to only 1,946, of whom 45 were Europeans, 1,521 were free natives, and 380 were freemen.