Amercement, or amerciament (derived, through the French 'a merci', from Latin 'merces', pay), in English law, an arbitrary pecuniary penalty, inflicted in old days on an offender by the peers or equals of the party amerced.
The word has in modern times become practically a poetical synonym for fine or deprivation. But an amercement differed from a fixed fine, prescribed by statute, by reason of its arbitrary nature; it represented a commutation of a sentence of forfeiture of goods, while a fine was originally a composition agreed upon between the judge and the prisoner to avoid imprisonment.
The fixing or assessment of an amercement was termed an affeerment. In the lower courts the amercement was offered by a jury of the offender's neighbours (affoerors); in the superior courts by the coroner, except in the case of officers of the court, when the amount was affeered by the judges themselves. All judgments were entered on the court roll as 'in mercy' (sit in misericordia), and the word misericordia, or some contracted form of it, was written on the margin.
Articles twenty to twenty-two of Magna Carta regulated the assessment of amercements.
See Stephen, History of Criminal Law; Pollock and Maitland, History of English Law; W. S. McKechnie,Magna Carta (1905).
Being the entry for AMERCEMENT in the 1911 Encyclopedia Britannica, the text of which lies within the public domain.