Both the Kings and the Pope always fought against each other on the question who has the supreme authority over their lands. The concordat of worms was a fair compromise because it gave Kings right to assign secular duties to church officials such as bishops, but it forbade them from having any religious authority over bishops who still answered to the pope. This meant that the king couldn't just put a Bishop that liked him in charge and spread his own idea of religion over the lands, but at the same time the Bishops would be allowed to do secular things in governing where religion would not affect them.
