The Order of Aviz was Portugal’s great national military order, born of the Reconquista in the Alentejo and affiliated to Calatrava. Its most famous master, João, seized the Portuguese throne in 1385 as John I and founded the House of Aviz — so that a military order gave its name to a royal dynasty and a golden age.
The Order of Aviz was the chief military order of medieval Portugal — the kingdom’s own instrument of the Reconquista, modelled on and affiliated to the Castilian Order of Calatrava. It held the Alentejo frontier and shared in the making of Portugal.
Its place in history was sealed when its master, João, became King John I in 1385 and gave the name of the order to the royal House of Aviz, which would rule Portugal through the age of discovery.
The order emerged around 1176 as a brotherhood of knights at Évora, in the newly conquered Alentejo, and was affiliated to Calatrava, whose Cistercian rule and green-lily cross it adopted. In the early 13th century it received the town of Avis and moved its headquarters there, taking the name it has kept since.
As a daughter-order of Calatrava it stood under Castilian visitation, a tie that Portugal’s kings would strain as they built a national order of their own.
When the Portuguese royal line failed in 1383, the master of Aviz — João, an illegitimate son of King Peter I — became the focus of resistance to a Castilian succession. Acclaimed king in 1385, he defeated Castile at the Battle of Aljubarrota that same year and secured Portuguese independence.
As John I he founded the House of Aviz. The order’s name now belonged to a dynasty, and its mastership passed permanently into the orbit of the crown.
After 1385 the mastership of Aviz was held by royal princes, binding the order ever closer to the throne. Its knights and revenues served the crown’s wars in Iberia and, in time, its ventures in North Africa.
The green cross of Aviz became a badge of the Portuguese establishment, worn by the nobles of the dynasty that carried its name.
The Order of Aviz survives as one of Portugal’s honorific orders, but its deepest mark on history is the dynasty it named. The House of Aviz — John I, John II, and Manuel I — presided over Portugal’s rise as a maritime power.
Alongside the Order of Christ, Aviz shows how the military orders became fused with the Portuguese crown at the dawn of the age of discovery.