A Portuguese military religious order, originally known as the Order of Évora. The first definite information about the order dates from 1176; it did not adopt the name of Avis until 1215.
The claims of medieval chroniclers that date the foundation of the order to the mid-twelfth century are unfounded. The conclusions of Rui Pinto de Azevedo are now held to be the most authoritative: he demonstrated that the origins of the order should be situated in Évora, and should be placed between March 1175 and April 1176 [Azevedo, “As origens da ordem de Évora ou de Avis”]. At this time King Afonso I Henriques of Portugal, thanks to a truce with the Almohads, was attempting to elaborate a defensive strategy that would ensure the advanced positions of his kingdom against al-Andalus in the Alto Alentejo region (mod. central Portugal). In 1211 the brethren of Évora were given the fortress of Avis, from which they took their new name a few years later. It is unclear why the brethren left their original Benedictine obedience in 1187 and sought association with the Castilian Order of Calatrava, which followed the Cistercian rule. This new dependence was evident in the prerogatives given to the master of Calatrava: he had rights of visitation over the Order of Avis and was also allowed to govern the institution whenever a vacancy in its mastership occurred, which he did until the mid-fourteenth century.
The Order of Avis was composed of knight brethren and clerics. They wore a scapular, which from 1404 bore a green cross on the left side. Under the aegis of its master, the institution gradually gained strength during the first part of the thirteenth century. Supported by the Portuguese monarchy, the brethren were active in the reconquest of the Iberian Peninsula from the Moors, acquiring lands in the process. By the late thirteenth century these properties were organized in a network of no fewer than twenty-five comman- deries: the richest of these were concentrated on the left bank of the river Tagus (Port. Tejo) near Avis, and also further south in the newly conquered areas, where the brethren had settled in Évora, Alandroal, Juromenha, Noudar, and Albufeira.
Such extensive land-ownership alarmed the Portuguese monarchy, which felt threatened by the potential power of the order. In the reign of King Dinis (1279-1325), royal policy toward Avis changed radically: the king put an end to donations and began supporting urban oligarchies and Muslim minorities in jurisdictional disputes, even in the town of Avis itself, thus deliberately harming the order’s interests. The masters of Avis were increasingly selected from among the king’s followers, or even his relatives. This can be seen in the case of the Infante John (Port. Joāo), a natural son of King Peter I who was made the master of the order in 1364 at the age of seven, twenty years before ascending the throne of Portugal.
John became king after a two-year civil war, an event that could only reinforce royal interference in the order. After defeating his Castilian rival in 1385 in the battle of Aljubarrota, John I tried to maintain control by appointing a faithful follower, Fernāo Rodrigues de Sequeira, as master of Avis. When the latter died in 1433, John decided that a master of royal blood would be best able to control the order, and appointed his own son, the Infante Fernāo (Ferdinand). This master had to relinquish his position just before his death (1443) after being captured in Tangier. His successor was Pedro, his own nephew and son of Infante Pedro, the regent of the kingdom. Despite a period of exile, Pedro succeeded in keeping his office until his death in 1466. The mastership was then given to the Infante John, the elder son of King Afonso V; he remained master after ascending the throne in 1481. Nine years later John II gave the mastership to his heir, the Infante Afonso, and then to the Infante Jorge, his own natural son. The latter paved the way for the eventual absorption of the order by the Portuguese Crown, which occurred in 1550.