Spain’s colonial empire in north and Central America (Spanish empire). The formation of the viceroyalty of New Spain began in 1518 with Cortés’s attack on the Aztec empire in central Mexico. Following his destruction of Aztec power, Cortés erected a new capital at Mexico City and was named governor and captain-general of New Spain (1522). He and his lieutenants extended Spanish authority south into Salvador, Guatemala, and Honduras, and north into the Mexican hinterland. New Spain grew to encompass California, the American south-west, and Florida, although Spanish settlement in many areas was very limited. In the 18th century Spain’s involvement in European wars had affected its colonial possessions. In 1763 it ceded Florida to Britain and received Louisiana from France, regaining Florida in 1783, but being forced to return Louisiana to France in 1800.