The Antoninos

Relating to a marriage between a noble and a person of inferior rank in which the rank of the latter remains unchanged and the children of the marriage do not succeed to the titles, fiefs, or other property of the parent of higher rank.

"Morganatic" actually comes from a word for a marriage benefit, "morganatica" meaning "morning gift" and refering to the gift that a new husband traditionally gave to his bride on the morning after the marriage.

The phrase "matrimonium ad morganaticam", literally "marriage with morning gift," means just that - the wife got the morning gift, but that’s all she was entitled to of her husband’s possessions...