Why did Henry IV travel to Canossa in 1077?

Henry IV traveled to Canossa in January 1077 to seek absolution from Pope Gregory VII after being excommunicated and deposed by the pope during the Investiture Controversy.123

Following his excommunication in 1076, Henry faced a rebellion from the German nobility, who threatened to elect a new king at an assembly in Augsburg unless he obtained absolution from the ban within a year. To prevent his deposition and undermine the opposition's political arguments, Henry secretly traveled to Italy to meet the pope.123

At the castle of Matilda of Canossa, Henry performed public penance—reportedly waiting barefoot in the snow for three days—until the pope lifted the excommunication. While this act was a tactical political success that allowed Henry to reestablish his authority in Germany, it also marked a significant shift in the balance of power, as Henry’s submission implicitly acknowledged the pope's authority over the secular ruler.231