The term Walk to Canossa , sometimes called the Humiliation of Canossa , refers to the trek of Henry IV, Holy Roman Emperor from Speyer to Canossa Castle in Emilia-Romagna to obtain the revocation of the excommunication imposed on him by the Pope Gregory VII. He was forced to humiliate himself on his knees waiting for three days and three nights before the entrance gate of the castle, while a blizzard raged in January 1077.