Germany during the Crusades
Henry IV (1056-1106) and Henry V (1106-1125)
At the time of the First Crusade, Henry IV was still very much preoccupied with his conflict with the papacy and with rebellions in Germany. One of those rebels was his own son and future emperor, who inherited his father's dispute with the popes and who, in his turn, was likewise faced with endless rebellions.
The reign of these two men covered three-quarters of a century, and they established a pattern that would be repeated, in varying forms, in later decades. Faced with titanic struggles outside Germany, the emperors were unable to reduce their barons to obedience. Their most-favored response for dealing with this was to turn instead to the Church for support, rather than to the princes. This is a major reason why the dispute over investiture, an issue in nearly every kingdom, loomed so large in Germany. If the barons could not be relied upon, and the clergy could not be controlled, then how could the kings form a strong government? It turned out that the answer was: they could not, and power in Germany remained decentralized, in the hands of the great princes.
Henry V died without a son to inherit, and for the first time in a century, the imperial succession was open to question. It shouldn't have been, for Henry had designated his nephew, Frederick of Swabia, but too many powerful princes opposed this choice. Instead, they chose Lothair, Duke of Saxony, one of the leaders of the opposition to Henry V.