Campo Maior is a municipality in the Portalegre District, Alentejo Region, Portugal. The population in 2011 was 8,456, in an area of 247.20 square kilometres (95.44 sq mi). It is bordered by Spain on the North and East, by Elvas Municipality on the Southeast, and by Arronches Municipality on the West.

Amadeus of Portugal, born João de Menezes da Silva, was a Portuguese nobleman who became first a Hieronymite monk, then left that life to become a friar of the Franciscan Order. Later he became a reformer of that religious order, which led to his founding of a distinct branch of the Friars Minor that was named after him, but later suppressed by the Pope in order to unite them into one great family of Friars Minor Observants (1568).