History

Pic: A woodcut of a medieval wedding ceremony from Germany

Marriage of some kind exists in nearly every society. Except in societies where post-marital residence is traditionally matrilocal, patrilocal, or avunculocal, married people typically form a household, which is most often a subsequently extended biologically, through children. Among Western cultures, the nuclear family emerged during the late medieval period. ost non-Western societies have a broader definition of family that includes an extended family network. Marriage is the sole mechanism for the creation of affinal ties (in-laws).

Although the institution of marriage pre-dates reliable recorded history, many cultures have legends or religious beliefs concerning the origins of marriage.

In Britain
Marriage remains relevant as the union that socially sanctions a sexual relationship. In the law of England and Wales, children whose parents were not married to each other at the time of the birth were known as bastards. They were considered illegitimate, meaning they usually could not inherit wealth or title. This has also applied to children who were born inside a marriage which was then annulled; the two daughters of Henry VIII, Mary I and Elizabeth I, were declared illegitimate after their father annulled the marriages that they had been born into.
In Catholicism, the Council of Trent made the validity of marriage dependent upon its being performed before a priest and two witnesses. The Council also authorized a Catechism, issued in 1566, which defined marriage as, "The conjugal union of man and woman, contracted between two qualified persons, which obliges them to live together throughout life."

Marriage has changed throughout the history of Europe, in the 1200's in England it was unlawful for a woman younger than 24 years to marry but this changed in the beginning of the 1500's to 20 years of age.

In the Middle Ages the Church only allowed divorce for consanguinity and adultery but during the reformation, Luther and others made marriage a civil institution instead of a sacramental one. This made way for the right of women to divorce their husbands for his faults such as impotence.

In the United Kingdom, the Deceased Wife's Sister's Marriage Act 1907 was a statute passed by Parliament that removed the prohibition forbidding a man to marry the sister of his deceased wife.

European monogamy
European culture and the cultures of the Americas, so far as they descend from it, have for the most part defined themselves as monogamous cultures. This partially stemmed from Christianity, Germanic cultural traditions [verification needed] and the mandate of Roman Law. However, Roman Law permitted prostitution, concubinage, and sexual access to slaves. The Christian West formally banned these practices with laws against adultery, fornication, and other relationships outside a monogamous, lifelong covenant.