Final answer:
Martin Luther became an outlaw by the Edict of Worms, issued in 1521 after his refusal to recant his writings.
Step-by-step explanation:
Martin Luther was made an outlaw within the Holy Roman Empire by the Edict of Worms. This edict was a result of his refusal to recant his writings at the Diet of Worms, a council held by the Holy Roman Emperor in the German city of Worms. The Edict of Worms issued in 1521, declared Martin Luther an outlaw and heretic and banned the reading or possession of his writings.