The Order of Saint Mary of Montesa and St. George of Alfama is a religious and military order founded by King James II of Aragon in the 14th century (1317). It currently survives as a corporation of an honorary and noble character

The King of Aragon gave to the order the Castle of Montesa, located near the border with the Saracens in the Kingdom of Valencia. It was approved by Pope John XXII on June 10, 1317, by bull, approving and confirming the Order of Montesa as proposed by King James II of Aragon, investing the goods of the order of the Templars extinguished by Clement V in endowing a new order that sought to found the aforementioned king.

The foundation was verified on Sunday, July 22, 1319, in the royal chapel of the palace of Barcelona, being the head and sacred convent of it that of the town of Montesa, of which the king made donation to the order, and of which he took its name. He took a red cross without flowers, and the white capitular mantle which Clement VII approved on 5 August 1397. But later, on the occasion of having incorporated into this order in 1399 that of St. George of Alfama, he left that badge and adopted a cross of red gules by concession of Benedict XIII, granted in 1400 and which Martin V later confirmed. The order suffered numerous difficulties.

According to the foundation bull, it was the master of Calatrava who was responsible for the creation of the new order, as well as the ability to arm the knights and make the Montesan knights dress.

James II, in advance, had written the teacher of Calatrava to accelerate the action. The master, who did not like to obey orders or his own king, that of Castile, did not even answer the letters. The king then went to the pope to give the order to that of Calatrava. The Pontiff passed the commission to the archbishop of Valencia, who also did not receive a response from the Master of Calatrava. The Archbishop of Valencia finally sent to Castile the abbot of the Monastery of Our Lady of Benifassà, belonging to the Order of the Cistercle.

The Master of Calatrava refused to go to Valencia, claiming that his obligations guarding the border prevented him, although the real reason seems to be that it was the unwillingness on the part of the Order of Calatrava to cede the possessions of Aragon to another order. Finally, he gave in and sent a prosecutor to Valencia to work on his behalf

• Evolution Foundation of the Order of Montesa. William of Eril, an old man, a great expert in the military arts, was named as the first Master of the New Order. The office lasted him very little, as Eril died seventy days after he was elected. The kingdom of Valencia was agitated due to the revolt known as the Union, by which some Valencian nobles, relying on the people, wanted to emancipate themselves from the tutelage of the Kingdom of Aragon and constitute themselves in an independent kingdom.

The king of Aragon commissioned the Master of Montesa, Arnaldo of Ferriol, to control the seditious, thus becoming the Montesans a very important asset for King Pedro IV of Aragon to defeat the rebels of Valencia. The Order became the main military force defending the throne.