Prohibited degrees of relationship for marriage as given in Burn's ECCLESIATICAL LAW 1848. The table actually dates back to 1563.
One should note that having carnal knowledge brings the prohibitions into force. So having sex with one woman means a man can't legally marry her sister. Of course, the first act perhaps not being provable, this wasn't always enforced.This led to a longer table as follows.
A man may not marry his: grandmother, grandfather's wife, wife's grandmother, father's sister, mother's sister, father's brother's wife, mother's brother's wife, wife's father's sister, wife's mother's sister, mother, stepmother, wife's mother, daughter, wife's daughter, son's wife, sister, wife's sister, borther's wife, son's daughter, daughter's daughter, son's son's wife, daughter's son's wife, wife's son's daughter, wife's daughter's daughter, brother's daughter, sister's daughter, brother's son's wife, sister's son's wife, wife's brother's daughter, wife's sister's daughter.
A woman may not marry her: grandfather, grandmother's husband, husband's grandfather, father's brother, mother's brother, father's sister's husband, mother's sister's husband, husband's father's brother, husband's mother's brother, father, stepfather, husband's father, son, husband's son, daughter's husband, brother, husband's brother, sister's husband, son's son, daughter's son, son's daughter's husband, daughter's daughter's husband, husband's son's son, husband's daughter's son, brother's son, sister's son, brother's daughter's husband, sister's daughter's husband, husband's brother's son, husband's sister's son.
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