Friday the 13th of October 1307 most of the Knights Templar were arrested and after a series of trialsput to death. That is the orign of the superstition.
Esther 3:12 Then on the thirteenth day of the first month the royal secretaries were summoned. They wrote out in the script of each province and in the language of each people all Haman’s orders to the king’s satraps, the governors of the various provinces and the nobles of the various peoples. These were written in the name of King Xerxes himself and sealed with his own ring. 13 Dispatches were sent by couriers to all the king’s provinces with the order to destroy, kill and annihilate all the Jews—young and old, women and little children—on a single day, the thirteenth day of the twelfth month, the month of Adar, and to plunder their goods. 14 A copy of the text of the edict was to be issued as law in every province and made known to the people of every nationality so they would be ready for that day.