Meeting of the Diet (assembly) of the Holy Roman Empire at Worms, Ger.
, in 1521, where Martin Luther defended the principles of the Reformation . Luther had already been excommunicated by Pope Leo X , but Emperor Charles V granted him safe conduct to a hearing at the Diet. On April 17, 1521, Luther refused to recant his views. Disorder broke out, the emperor adjourned the proceedings, and Luther was obliged to go into hiding. In May the Diet issued the Edict of Worms, declaring Luther an outlaw and a heretic and banning his writings.