#historyonleo #onthisday On January 28th 1077 Henry IV, Holy Roman Emperor is allowed to enter Canossa Castle, held by Matilda of Tuscany, and humbles himself before Pope Gregory VII, asking for forgiveness. This symbolic gesture, which confirmed papal supremacy over power of emperors, is one of the crucial episodes of Investiture Controversy, which was cause of long civil strife in Germany and Italy. Pope Gregory VII lifted excommunication of Henry IV, but the peace didn't last. After Gregory VII supported uprising against emperor, Henry IV invaded Italy, took Rome and exiled Gregory VII. Phrase "walk to Canossa" nevertheless entered European vocabularies as synonym for humiliating penance in front of archenemy.