The Knights Templar were an armed religious order established in 1118 during the Crusades to aid and protect pilgrims making their way to the Holy Land. They had a considerable presence in Ireland and at one stage were the owners of Clontarf Castle.
In spite of their vows of poverty, the Knights Templar became extremely wealthy, owning a large number of properties throughout Europe. As the increasing power of the Templars became evident, King Philip of France grew jealous and fearful of their influence. He had also borrowed large sums of money from the Templars which he knew that he could not repay. He convinced Pope Clement V to order the arrest of the Templars in France. This order was given on Friday the 13th of October 1307, which is why any Friday the 13th is now considered to be a day of bad luck. Many of the Templars were brutally tortured into confessing to heretical crimes. From these confessions, the Pope ordered the suppression and arrest of the Templars throughout Europe.
In Ireland the trial of the Templars was less of a spectacle than in mainland Europe as the Irish Templars were spared the torture endured by their European counterparts. They were arrested on February 2nd 1308. All Templar property was seized by King Eward II. The men were held in Dublin Castle where they waited for an entire year before their jurors arrived to decide their fate. The inquisitors were a group of five men made up of Dominicans and Franciscans, chosen for their loyalty to the Pope. The trial took place in St Patrick's Cathedral which would then have been on the outskirts of Dublin city. It began on the 6th of February 1310 and lasted for four months. The charges were heretical in nature, denying Christ, worshipping idols, and spitting on the cross. Though there was no solid evidence the Templars were convicted. All of their posessions and lands were given to the Knights of St John of Jerusalem, known today as the Order of Malta. Though the Templars in France were burned at the stake, it seems that the Irish Templars were spared such a fate and allowed instead to enter into monastic life to serve their penance.
Read about the rise and fall of the Knights Templar here.