HALLER, BERTHOLD Swiss reformer, was born at Aldingen, Wurttemberg, and after studying at Pforzheim, where he met Melanchthon, and at Cologne, taught in the gym nasium at Berne. Even before his acquaintance with Zwingli in 1521 he had begun to preach the Reformation, his sympathetic character and his eloquence making him a great force. In 1526 he was at the abortive conference of Baden, and in January 1528 drafted and defended the ten theses for the conference of Berne which established the new religion in that city. He left no writings except a few letters which are preserved in Zwingli's works. He died on Feb. 25, See C. Pestalozzi, Berthold Haller (Elberfeld, i861).