During this man's reign, he put to death a religious revolutionary, who was condemned at the Second Lateran Council and the Synod of Sens, Arnold of Brescia.
Early in this man's reign, he became involved in a Danish civil war between Swend III and Valdemar I. This ruler recognized his greatest rival in the Peace of Anagni, which would be confirmed in the Peace of Venice. During this man's reign, he put to death a religious revolutionary, who was condemned at the Second Lateran Council and the Synod of Sens, Arnold of Brescia. While besieging the town of Ancona, this man, who endorsed the anti-pope Victor IV, won a major victory over Oddo Frangipani at Monte Porzio. This leader held a council which saw him attempt to assert his sovereignty over a group of cities, the Diet of Roncaglia, and that same group of cities would later defeat at Legnano. At the Diet of Mainz, this man was able to compel Richard the Lionhearted to join him on expedition to take back Jerusalem from Saladin. For ten points, name this Holy Roman Emperor, whose sobriquet reflected his red-beardedness.
Early in this man's reign, he became involved in a Danish civil war between Swend III and Valdemar I.
 Frederick I or Frederick Barbarossa