Johann Tserclaes Tilly, count, a German soldier, born in the castle of Tilly, Brabant, in February, 1559, died in Ingolstadt, April 20 (O. S.), 1632. He was educated at a college of Jesuits, first served in the Spanish army in the Netherlands, and in Hungary distinguished himself against the Turks. In 1610 Duke Maximilian of Bavaria appointed him field marshal. On the opening of the thirty years' war he was placed at the head of the army of the Catholic league, and contributed to the victory of Prague, Nov. 8, 1620; in 1621 he drove Count Mansfeld, the stanchest supporter of the Protestant cause, from Bohemia and the Upper Palatinate; in 1622 defeated the margrave of Baden at Wimpfen on the Neckar, and Christian of Brunswick at Hochst; and in 1623 routed the latter once more at Stadtloo. When Christian IV. of Denmark joined the German Protestants, he signally defeated him at Lutter in August, 1626. He next besieged Nordheim, which he took after a hard struggle, crossed the Elbe, and cooperated with Wallenstein in conquering the continental part of Denmark. In 1630 he succeeded Wallenstein as chief commander of the imperial armies. On May 10, 1631, he carried Magdeburg by storm, and allowed his soldiers to burn most of the town and massacre about 25,000 persons.

But in the same year (Sept. 7) he was utterly defeated by Gustavus Adolphus at Breitenfeld, near Leipsic, and vainly tried to recover his prestige. He was mortally wounded in an engagement with Gustavus at the river Lech near Rain, April 5, 1632. He declined the title of count of the empire and the principality of Kalenberg, was a devoted Catholic, and boasted of his temperance and chastity. - See Klopp's Tilly im dreissigjahrigen Kriege (2 vols., Stuttgart, 1861).