IIRC my history, the Templar's had become rich and the bankers of Europe. Phillip of France owed them a lot of money and in order to get our of paying them convinced the Pope to declare them heretics. Can't remember what the Pope got but it was a notorious time of church corruption. With this done Phillip was able to destroy them. Apparently the orders grand master was burned at the stake on Friday the thirteenth, giving us this unlucky date. I also read a book, for whatever it's worth, by a couple of Masons claiming the Masons were descended from the Templars and also that the Shroud of Turin was the robe that Jacques de Molay wore when he was nailed to a door before they burnt him.
Here's a better history.
http://www.templarhistory.com/philip.html