The Order of Aviz was a military and religious order founded in the 12th century in Portugal. It originated from the earlier Order of Calatrava, which was established to protect Christian territories during the Reconquista. The Aviz knights played a crucial role in defending Portugal against Muslim forces and were instrumental in the country's expansion. In 1319, the Order of Aviz became an independent entity, and it was closely associated with the Portuguese monarchy. The order's most famous member was Prince Henry the Navigator, who promoted exploration and maritime trade during the Age of Discoveries. The order eventually merged with the Order of Christ in the 16th century.