On charges of heresy, fifty-four Knights Templar are burned at the stake in France. King Philip IV the "Fair" of France had been deeply in debt to the Templars — they are very wealthy have loaned him large amounts of money to help him finance his various wars.
Now he's getting rid of his debts by eliminating the people he owes money to. King Philip is only able to achieve this, however, through the collusion of Pope Clement V, who has ordered the arrest of Templars throughout the rest of Europe and the confiscation of all their property — for the benefit of the church, of course.
Scholars debate whether any charges against the Knights Templar are true, but the general consensus is that they are innocent of the accusations. They are only attacked to get access to their wealth and prevent them from ever becoming a political threat.