In France: a body of vassals summoned for military service by order of the king; (also) the order containing such a summons. Also occasionally in extended use, with reference to similar gatherings elsewhere.
The specific application of the term has varied depending on the period or country referred to; often, especially in later use, a distinction is made between a ban and an arrière-ban, with the latter denoting a larger body including those who are not direct vassals of the king.
Early 16th century; earliest use found in 2nd Baron Berners (c1467–1533), soldier, diplomat, and translator. From Middle French arriere-ban, French arrière-ban body of vassals summoned for military service by order of the king, order containing such a summons, folk-etymological alteration (after arriere backward, behind: see note) of Old French herban from an unattested Frankish compound reflected in Old Frisian herabon, Old Dutch herban (Middle Dutch heerban, Dutch (now hist.) heerban), Old High German heriban (Middle High German herban, German (now hist.) Heerbann) from the Germanic base of here + the Germanic base of ban.