Morganatic marriage, legally valid marriage between a male member of a sovereign, princely, or noble house and a woman of lesser birth or rank, with the provision that she shall not thereby accede to his rank and that the children of the marriage shall not succeed to their father’s hereditary dignities, fiefs, and entailed property.

The name is derived from the medieval Latin matrimonium ad morganaticum, variously interpreted as meaning “marriage on the morning gift” (from German Morgengabe), with the implication that this morning gift, or dowry, was all that the bride could expect; or “restricted marriage” (Gothic maurjan, “restrain”); or simply “morning marriage,” celebrated quietly at an early hour.

Essentially a German institution, it was adopted by some dynasties outside Germany but not by those of France or England. The practice ensues from the German notion of Ebenbürtigkeit, or Gleichbürtigkeit (evenness or equality of birth), which in the European Middle Ages had a widespread application in German law. It required that parties to many sorts of transaction be of the same standing or estate, but it could not be an impediment to marriage in the law of the church.