Morganatic (adj.), morganatically (adv.)
In the context of European royalty, a morganatic marriage is a marriage between people of unequal social rank, which prevents the passage of the husband's titles and privileges to the wife and any children born of the marriage. Now rare, it is also known as a left-handed marriage because in the wedding ceremony the groom traditionally held his bride's right hand with his left hand instead of his right.
Generally, this is a marriage between a man of high birth (such as from a reigning, deposed or mediatised dynasty), and a woman of lesser status (such as a daughter of a low-ranked noble family or a commoner). Usually, neither the bride nor any children of the marriage has a claim on the bridegroom's succession rights, titles, precedence, or entailed property. The children are considered legitimate for all other purposes and the prohibition against bigamy applies. It is also possible for a woman to marry a man of lower rank morganatically.Etymology:
Morganatic, already in use in English by 1727 (according to the Oxford English Dictionary), is derived from the medieval Latin morganaticus from the Late Latin phrase matrimonium ad morganaticam and refers to the gift given by the groom to the bride on the morning after the wedding, morning gift, i.e. dower. The Latin term, applied to a Germanic custom, was adopted from a Germanic term, *morgangeba (compare Early English morgengifu, German Morgengabe, Danish and Norwegian Bokmål Morgengave, Norwegian Nynorsk Morgongåve and Swedish Morgongåva). The literal meaning is explained in a 16th-century passage quoted by Du Cange as, "a marriage by which the wife and the children that may be born are entitled to no share in the husband's possessions beyond the 'morning-gift'".
"Pushkin had four children from his marriage to Natalya: Maria (b. 1832, touted as a prototype of Anna Karenina), Alexander (b. 1833), Grigory (b. 1835), and Natalya (b. 1836) the last of whom married, morganatically, into the royal house of Nassau to Nikolaus Wilhelm of Nassau and became the Countess of Merenberg." Wikipedia Pushkin
(as pointed out by capt_facepalm--many thanks!)
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