In their broad outlines, the relations between Emperor Henry VI and the bishops of his realm differed only in degree from what they had been under Barbarossa. Henry relied heavily on the ecclesiastical princes, and they responded to his needs. Under Henry VI bishops are seen performing the customary servitia of supplying food and shelter during the emperor's visits to their cities; attending court; accompanying their lord throughout Germany and Italy; filling high offices of state; executing diplomatic missions; and joining in the emperor's crusade and military campaigns. Occasionally Henry encountered episcopal opposition and defiance, but normally the churchmen cooperated with him in his political endeavors. This was not an accident. Rather, such close collaboration resulted from Henry VI's policy of careful control over elections to the episcopal sees, so that men upon whom he could rely and whom he could trust secured these important offices and their resources.