Modern people often regard the idea of a holy war as a contradiction. Killing thousands of people and causing wholesale destruction seems to be as far from holiness as one can get.
But religion and war have gone hand in hand for a long time. Armies go into battle believing that God is with them, often after prayers and sacrifices to keep God on their side. In tribal cultures (including Biblical ones) when a people lose a war they often have to change to the worship of the winner’s gods.
However involving God as part of the campaign does not make a war a holy war – for a war to be a holy war, religion has to be the driving force.
Holy wars usually have three elements:
- the achievement of a religious goal
- authorised by a religious leader
- a spiritual reward for those who take part
Many of the wars fought in the name of religion do conform to the just war conditions, but not all of them.
Francis Bacon said there were five causes for holy war: (he wrote in a Christian context, but the categories would be usable by any faith)
- to spread the faith
- to retrieve countries that were once Christian, even though there are no Christians left there
- to rescue Christians in countries that were once Christian from ‘the servitude of the infidels’
- recover and purify consecrated places that are presently being ‘polluted and profaned’
- avenge blasphemous acts, or cruelties and killings of Christians (even if these took place long ago)
Only the first of these causes is completely outside the scope of the conventional idea of a just cause. Some of the other causes, because of the length of time that can pass since the offending act took place are probably not just causes either.
The legitimate authority for a holy war is not the government of a state (except in a theocracy) but the Church, or the relevant organisation or person who heads the religious institution concerned.
In ancient times the authority was often God – in the Bible there are several occasions where God gave direct instructions to peoples to wage war. This would not be the case today.
The third condition of a holy war is a spiritual reward for those who take part. The doctrine of the just war does not refer to any personal rewards for the participants – and such rewards would be against such a generally austere doctrine.
The first holy war was probably in October 312 CE when the Roman emperor Constantine saw a vision of the cross in the sky with this inscription “in hoc signo vinces” (in this sign you will win).
Constantine trusted the vision and had the cross inscribed on his soldiers’ armor. Even though his forces were outnumbered, he won the battle against an army that was using pagan enchantment. (Historians regard this as a turning point in Christianity’s fortune.)
The great series of western holy wars were the Crusades, which lasted from 1095 until 1291 CE. The aim was to capture the sacred places in the Holy Land from the Muslims who lived there, so it was intended as a war to right wrongs done against Christianity.
The first Crusade was started by Pope Urban II in 1095. He raged at the capture of the holy places and the treatment given to Christians, and ordered a war to restore Christianity. He said that the war would have the support of God:
Let this be your war-cry in combats, because this word is given to you by God. When an armed attack is made upon the enemy, let this one cry be raised by all the soldiers of God: It is the will of God! It is the will of God!
..Whoever shall determine upon this holy pilgrimage and shall make his vow to God to that effect and shall offer himself to Him as a living sacrifice, holy, acceptable unto God, shall wear the sign of the cross of the Lord on his forehead or on his breast.
The pope also absolved all who took part in the crusade of all their sins.
The first Crusade captured Jerusalem after bitter fighting, and the residents of the city were brutalised and slaughtered by the Christian invaders. The invaders’ conduct breached the principles of modern just war ethics, and the massacres still colour Islamic politics today.