The Pope was its sovereign, the Bishops were his barons, and the clergy were his under vassals.

As the king demanded aids and subsidies in case of need from his liegemen, so in the theory of Rome might the head of the Church demand aid in need from the priesthood.

And at this moment the need of the Popes was sore.

Rome had plunged into her desperate conflict with the Emperor, Frederick the Second, and was looking everywhere for the means of recruiting her drained exchequer.

On England she believed herself to have more than a spiritual claim for support.