Arrière-ban

In medieval and early modern France, the arrière-ban (Latin retrobannum) was a general proclamation whereby the king (or duke) summoned to war all the vassals of his vassals. The term is a folk-etymological correction of Old French herban (attested 1101), from Germanic here (army) and ban (proclamation); compare German Heerbann.

Although in theory, the arrière-ban depended on feudal relations, in practice it amounted to a general levy on all able-bodied males in the kingdom. In theory, this included all men between the ages of 18 and 60 years, in practice such a wide-ranging levy was never carried out for fear of conjuring an ill-suited mob. Most arrière-ban's were in fact local in nature. Conscription could be commuted by a money payment, which became an important source of revenue for the crown.