By following the Benedictine rule, arises from the habit of the origin of Calatrava orders and Avis – white, with a flordelisada cross (red, in the case of the Order of Calatrava, and green, Avis). Similarly, the establishment of this rule prevented its members from marrying (unlike other military religious orders whose members were laymen). However, concubinage was quite common, which led to Pope Alexander VI (in 1402) tolerate marriage as a way to prevent any concubinagens and excesses of convent life.
Afonso I of Portugal, would occupy Évora about 1165, and about 1175 would donate goods in the city, Intramuros, the Calatrava brothers settled in Portugal – where the first name of this militia in Lusitanian soil: the friars of Santa Maria de Évora or Militia of Santa Maria de Évora – to the populate, develop and organize.
Even, the first king would grant a his illegitimate son, Pedro Afonso, Avis order master, the position of first master of this order on Portuguese soil.
Although Evora Freires maintain obedience who owe the prior in Castile, but soon gained forums of ‘national policy’, especially from the moment moving on for Avis, that they had been donated in 1211 by King Alfonso II. Noble D. Martins de Avelar officially assumes the Master of the Order of Avis until his sudden death in the summer of 1364.
Around 1364, King Pedro I of Portugal delivers the master of the order to his bastard João relationship child with a Galician lady name Teresa Lourenço. It would be the same John who, after the death of Ferdinand, was to bring together numerous support in the fight against Beatriz of Portugal, the legitimate heir to the throne, winning the Spanish King John I in Aljubarrota and be declared king by the Cortes de Coimbra 1385.
The rise of John, Master of Avis, the throne of Portugal, dictated on the one hand, the integration of the master of this order in the Crown of Portugal (being appointed or royals, nobles or the entire confidence of the monarch, as was the case of the Grand Master first after King John, Fernando Rodrigues de Sequeira), and on the other, greater alienation with the Order of Calatrava; after 1385, the Order of the Knights refused to recognize the Spanish Grand Master, Gonzalo de Guzman, as his superior. This led to problems even with the Papacy (to which was added the positioning of both crowns during the Great Schism of the West, with John I of Portugal to support the Pope of Rome, and John I of Castile, the schismatic Avignon) only finally resolved with the council of Basel-Ferrara-Florence (1431).
Furthermore, the accession to the throne of a master of Avis gave rise to a canonical dispensation granted to celebrate marriage, since, under the Benedictine rule that Avis Order followed, members of the said Order professed a vow of chastity.
With the ascent to the throne of John I of Portugal rekindled the flame of war crusade, long lost in Portugal; the achievements in the Maghreb lead the religious orders to pastures new. Thus, the Knights of Avis (as well as the Christ, the other Portuguese national order) will be attending the conquest of Ceuta (1415), as well as in the failed attack on Tangier (1437), in which he was held (and eventually died in captivity reputation for holiness) Prince Fernando, who was then Master of the Order since 1434. By his death in Fez in 1443, passed the Master into the hands of the eldest son of the Regent Pedro, Duke of Coimbra, also called Peter (which would be for a brief period, King of Aragon).
The order was then inherited by Prince John (future John II of Portugal) for his illegitimate son George of Lancaster, and on the death of this in 1551 (reign of John III of Portugal), the Order of the Grand Masters Avis was incorporated perpetually to the Crown, losing all its religious character. That same year, Pope Julius III would allow their members to freely dispose of their property (also contrary to the vow of poverty made by its members). By this time, the only criterion that was needed for admission into the Order was to belong to the State of the Nobility, which was confirmed by a decree of 1604.
On August 1, 1789, Queen Maria I of Portugal, with the help of Pope Pius VI, tried to reform Avis order, but eventually only secularize them – the three orders – (Avis, Santiago and Christ) although he kept the integrated Grand Master still the Crown. This secularization settled the birth of the Band of Three Orders (a tripartite group of purple, red and green, respectively representing the Orders of Santiago, Christ and Avis), with which have since been awarded the Portuguese heads of state (kings or presidents) when his rise to power as a symbol of the judiciary exercising.
The order was also taken to Brazil by the Prince Regent D. John and in 1834, the Regent Pedro, Duke of Bragança, on behalf of the young Queen Mary II, completely abolished the order.