 In February 1777, a Spanish expeditionary force of 116 ships and 19,000 troops captured the island of Santa Catarina in February before moving against Colonia del Sacramento which surrendered in July.Fighting ended in February 1777 when Joseph I of Portugal died and his daughter, Spanish-born Maria I, sued for peace.The First Treaty of San Ildefonso signed on 1 October 1777 established a Boundary Commission to demarcate borders between the two Empires in the Río de la Plata region.