1. A marriage of the first degree which took place between partners of equal rank and property.
2. A marriage of the second degree in which a woman had less property than the man and was supported by him.
3. A marriage of the third degree in which a man had less property than the woman and had to agree to management of the woman's cattle and fields.
4. A marriage of the fourth degree was the marriage of the loved one in which no property rights changed hands, though children's rights were safeguarded.
5. A marriage of the fifth degree was the mutual consent of the man and woman to share their bodies, but live under separate roofs.
6. A marriage of the sixth degree in which a defeated enemy's wife was abducted. This marriage was valid only as long as the man could keep the woman with him.
7. A marriage of the seventh degree was called a soldier's marriage and was a temporary and primary sexual union (a one night stand).
8. A marriage of the eighth degree occurred when a man seduced a woman through lying, deception or taking advantage of her intoxication (equivalent to date rape).
9. A marriage of the ninth degree was a union by rape (forcible rape).
10. A marriage of the tenth degree occurred between feeble minded or insane people.
From "Marriage, Separation and Divorce In Ancient Gaelic Culture," by Alix Morgan MacAnTsaoir. Posted by Clannada na Gadelica