Frank"pledge` (?), n. [Frank free + pledge.] (O. Eng. Law) (a) A pledge or surety for the good behavior of freemen, -- each freeman who was a member of an ancient decennary, tithing, or friborg, in England, being a pledge for the good conduct of the others, for the preservation of the public peace; a free surety. (b) The tithing itself. Bouvier.

The servants of the crown were not, as now, bound in frankpledge for each other.