The island was used as a penal colony from 1765 until 1886. Developed by the Viceroyalty of the Río de la Plata, the first viceroy Pedro de Cevallos fortified the island and assigned a military garrison there. In 1814, Admiral William Brown, commanding a fleet, landed on the island and defeated the royalists, leaving Martin Garcia in the hands of the United Provinces of Río de la Plata.