Tilly, Johann Tserklaes, Count of. One of the great generals of the Thirty Years' War. Born in Brabant in 1559. Tilly was designed for the priesthood and educated by Jesuits, but abandoned the church for the army. He was trained in the art of war by Parma and Alva, and proved himself a born soldier. He reorganized the Bavarian Army, and, devoted to the Catholic cause, was given command of the Catholic army at the outbreak of the Thirty Year's War. During the course of that war, he won many notable battles, acting later on in conjunction with Wallenstein, whom, in 1630, he succeeded as commander-in-chief of the imperial forces. In the following year he sacked with merciless cruelty the town of Magdeburg, a deed which Gustavus Adolphus was swift to avenge by crushing the Catholic forces in two successive battles - Breitenfeld and Rain - in the latter of which Tilly was mortally wounded (1632).