The Order of the Knights of the Temple of Jerusalem - TEMPLÁRIOS - was born the idea of a crusade, which justified and legitimated an institution at the same time religious and military, voted the "holy war".

Do the "holy war" finds its legitimacy in one of the greatest Doctors of the Church, St. Augustine (345-430), which distinguishes the "unjust war", which condemns the "just war" that is lawful and in which any Christian must participate.

The "holy war" is not an end in itself but a means legitimate and necessary given by God and his vicar, the Pope, the believers to extend the kingdom of religion.

Company of salvation and redemption, the "holy war" implies a specific value of the fight against the infidels accompanied by various spiritual rewards.
The triumph of the Church can not do otherwise by the union and the sword of faith.
For St. Bernard of Clairvaux, made monk, who designed the Order as a "Militia of God" by it as a religion and armed militant.
Building on texts by St. Augustine on the right of lawful war, the popes who followed him, gave the Christians the right and duty to use the cross and fight to protect the church and release the seats occupied by infidels unfairly targeting the take by force Christians posts drop in servitude or threatened by Islam