Spanish navigator Juan Díaz de Solís was the first European to see the island, naming it for one of his crewmen who died there in 1516. In colonial times it often changed hands before coming under firm Spanish control in 1777; in 1814 Guillermo Brown, the Argentine navy’s Irish founder, captured it for the United Provinces of the River Plate. For a time, mainlanders quarried its granite bedrock for building materials.

For a century (1870–1970) the navy controlled the island, and it served as a political prison and a regular penal colony; it was also a quarantine base for European immigrants. While serving as Colombia’s consul in Buenos Aires, Nicaraguan poet Rubén Darío (1867–1916) lived here briefly.

Political detainees have included presidents Marcelo T. de Alvear (in 1932, after his presidency), Hipólito Yrigoyen (twice in the 1930s), Juan Domingo Perón (1945, before his election), and Arturo Frondizi (1962–1963). In World War II’s early months, Argentina briefly incarcerated German crewmen from the battleship Graf Spee, scuttled off Montevideo in December 1939.

While the island passed to the United Provinces at independence, it was not explicitly Argentine until a 1973 agreement with Uruguay (one of the United Provinces). After the navy departed, the Buenos Aires provincial Servicio Penitenciario used it as a halfway house for ordinary convicts, but it was also a detention and torture site during the 1976–1983 dictatorship.