 Because of this, Frederick I, as well as his son and successor Henry VI, tried to conciliate both events imagining a universal temporal empire, at whose front was an emperor with supreme authority, superior to the power of various kings, called "régulos" or "local kings".This supreme authority seemed necessary, because it was believed that the Empire was the way to maintain unity in Christianity in preparation for the end times.Without considering this eschatological and messianic element, one cannot correctly understand what the Empire meant for the men of the time, in particular for emperor Frederick I.