Sickingen, Franz von (fränts fən zĭˈkĭngən) [key], 1481–1523, German knight. Placed under the ban of the Holy Roman Empire because of his profitable forays along the Rhine, he served King Francis I of France and then made peace with Holy Roman Emperor Maximilian I, whose service he entered. His presence with an army near Frankfurt helped insure the election (1519) of Maximilian's grandson, Charles V, as Holy Roman emperor. Influenced by Ulrich von Hutten, Sickingen aided persecuted reformers like Johann Reuchlin and Martin Luther. He led (1522) the knights of SW Germany in a war, sometimes called the Knights' War, against the ecclesiastical princes, aiming at the secularization of ecclesiastical lands. Unsuccessfully laying siege to Trier, he was again put under the imperial ban and was besieged at his castle of Landstuhl by the princes of Trier, Hesse, and the Palatinate. Forced to capitulate, he died of his wounds. His defeat symbolized the end of the power of German knighthood. He appears, much romanticized, in Goethe's drama Götz von Berlichingen and in Wilhelm Hauff's novel Lichtenstein.