Smalcald (Ger. Schmalkalden), a town of Prussia, in the province of Hesse-Nassau (before 1866 of Hesse-Cassel), 34 m. E. N. E. of Fulda; pop. in 1871, 5,792. It manufactures iron, steel, and salt. - The Smalcald league was concluded here in 1531, by various Protestant princes and free cities, for mutual defence of their religious and political independence against Charles V. and the Catholic states of the empire. It was limited at first to six years, but in 1535 new members were admitted at a second convention in Smalcald, and the term was extended ten years, with a reso-lution to maintain an army of 12,000 men. The elector John Frederick of Saxony and the landgrave Philip of Hesse became the leaders of the league, whose war against the emperor (1546-'7) was terminated by the victory of the latter at Muhlberg, April 24, 1547. In 1537 a confession of faith was drawn up in several articles by Luther, known subsequently as the "Articles of Smalcald," which became one of the symbolical books of the Lutheran church.