German soldier and devoted servant of the Habsburgs who fought on behalf of the Holy Roman emperors Maximilian I and Charles V.

In 1499 Frundsberg took part in Maximilian's struggle against the Swiss, and, in the same year, he was among the imperial troops sent to assist Ludovico Sforza, duke of Milan, against the French. Still serving Maximilian, he took part in 1504 in the war over the succession to the duchy of Bavaria-Landshut, and afterward he fought in the Netherlands. Frundsberg is often called the “father of the Landsknechte” because he played a prominent part in the organization of that formidable mercenary infantry, armed with pike and sword, which became Maximilian's most powerful striking force. As commander of the Landsknechte, Frundsberg was of great service to the empire in 1509, 1513, and 1514 against the Venetians and the French. When the struggle between France and the empire was renewed, he took part in the invasion of Picardy (1521). Proceeding to Italy, he brought most of Lombardy under the influence of Charles V through his victory at Bicocca in April 1522. He was partly responsible for the great victory over the French at the Battle of Pavia in February 1525. Returning to Germany, he helped to suppress the peasants' revolt, using on this occasion diplomacy as well as force.