The banns of marriage, commonly known simply as the "banns" or "bans" (from a Middle English word meaning "proclamation," rooted in Old French) are the public announcement in a Christian parish church

Parish church

A parish church , in Christianity, is the church which acts as the religious centre of a parish, the basic administrative unit of episcopal churches....

 of an impending marriage

Marriage

Marriage is a social union or legal contract between people that creates kinship. It is an institution in which interpersonal relationships, usually intimate and sexual, are acknowledged in a variety of ways, depending on the culture or subculture in which it is found...

 between two specified persons. It is commonly associated with the Church of England

Church of England

The Church of England is the officially established Christian church in England and the Mother Church of the worldwide Anglican Communion. The church considers itself within the tradition of Western Christianity and dates its formal establishment principally to the mission to England by St...

 and with other denominations whose traditions are similar; the Roman Catholic Church abolished the requirement in 1983.

The purpose of banns is to enable anyone to raise any canonical

Canon law

Canon law is the body of laws & regulations made or adopted by ecclesiastical authority, for the government of the Christian organization and its members. It is the internal ecclesiastical law governing the Catholic Church , the Eastern and Oriental Orthodox churches, and the Anglican Communion of...

 or civil

Civil law (common law)

Civil law, as opposed to criminal law, is the branch of law dealing with disputes between individuals or organizations, in which compensation may be awarded to the victim...

 legal impediment to the marriage, so as to prevent marriages that are invalid.