ABSTRACT
Early medieval armies frequently lacked the sheer professional skill required for the successful pursuit of the siege of a strong castle, and there are a number of instances, especially from France, of powerful princes being held up for humiliatingly long periods. Professionalism among fighting-men, under the comparison of the Byzantine army and the Military Orders, was bound to grow as a result of the Crusades; but there was another professionalism. It is the technical skill of miners who could undercut the angles of a fortress, the skill of expert carpenters to make siege-engines. The increase in professionalism and the added power it gave to the attacking force might be expected to put a greater call on the knowledge and energies of the builders of castles. M. Gebelin gives an architectural history of the castle of Gisors (Eure) which ascribes to Henry I of England, in 1123, the building of the main ward.
