Wednesday 16 September 2009

The topic of consanguinity in marriage came up in the comments, so I started wondering about the rules—this heretofore being an issue I have mostly ignored in the story.


Consanguinity is the relationship between people related by blood—one being the ancestor of the other (direct consanguinity), or both having a common ancestor (collateral consanguinity). For very close blood relationships this can cause an increase of genetic disorders, since the risk of both parents being silent carriers of a malady increases if they are genetically closely related. I don’t know how aware people were of that in the Dark Ages, but in any case the Church did not look kindly on marriages between closely-​related people.

Marriages involving direct consanguinity are forbidden, no matter how many generations separate the couple. So no marrying of the parent, grandparent, etc. In a collateral relationship, the people must be separated by an appropriate number of “degrees” from each other (unless one is Kevin Bacon). So no marrying of nieces, first cousins, etc. However, at different periods the number of degrees and even the calculation of degrees could vary, so here’s what I have learned about my own period from my half-​hour of research. (I told you this story is not a serious historical work.)


The first way to calculate relationships is according to civil law: in this technique you count the number of “hops” between one person to the other along the family tree. So for a pair of siblings you have two hops (Dunstan to Alred, Alred to Gwynn), for an aunt and nephew you have three (Eadie to Leofric, Leofric to young Sigefrith, Sigefrith to Haakon), and for first cousins you have four (Magog to his father, his father to his grandfather, his grandfather to Man-​Flann, Man-​Flann to Connie).

According to Canon Law, however, it’s counted only by the number of hops to the common ancestor, along the longest branch. So in case of siblings it is 1, aunt and nephew it is 2 (Haakon to Sigefrith, Sigefrith to Leofric), and in first cousins it is also 2.

Application by the Church

In early medieval times, back in Rome and the vicinity, the less-​strict civil calculation was used. At least since 732, consanguinity was disallowed among the “Germans” (i.e. Northern Europeans) as far as the seventh degree. This is already pretty strict: Ogive and Leof (first cousin, once removed) are only five degrees separated, for instance. To get to eight degrees of separation we would have to go as far as Leofric and one of Synne’s twins.

Still, when the Roman Church was busy converting all the barbarian hordes—not so very distant from our time period: remember Sigefrith’s grandfather was raised as an Odin-​worshipping pagan—it was decided that to promote inter-​tribal marriage and hence promote peace, it would be wise to make rules about consanguinity stricter. Thereafter the Canon calculation started to be used. At that point, practically everyone in a small community would now be too closely-​related to marry, and likewise most of the noble families of Europe.


However, for more distant degrees the rules weren’t strictly prohibitive, and it was customary to apply to the Pope or a local bishop for a dispensation… for a fee, of course. Also, such distant relationships would often have been unknown, and if it later became known that a couple was related, a marriage contracted in ignorance of a distant relationship would be dispensed rather than annulled. But in theory, even if you unknowingly married a relative, you would be required to separate from that person but be forbidden to take another spouse. So at least in theory, you couldn’t weasel out of an unhappy marriage by suddenly discovering a blood relationship.

Also, certain very close degrees of consanguinity were simply never granted dispensation, particularly direct consanguinity. You were never going to be allowed to marry your sister, no matter how much you begged the Pope.


Affinity is a similar impediment to marriage, but this is based on laws against marrying the relatives of your spouse. By marrying someone, you effectively became related to his family through affinity such that you are considered related to them by the same degree as if you were your spouse. Thus you could not marry your dead husband’s brother, because they are too closely related; nor your dead husband’s uncle, his first cousin, etc.

Worse, before the Fourth Council of Lateran (1215), affinity was “transitive”—if your sister married a man, you were now related to that man’s family too. If your first cousin married a man, you were now related to that man’s family too. Thus Osh ought not to have been allowed to marry Flann because Flann’s sister is married to Osh’s son. (I’m not sure what degree that would be, but it’s clearly too close.)

However, fortunately, the Church was willing to consider granting dispensation to any degree of affinity—even marrying your dead husband’s brother or father. Not to say it would always grant it, but it was not strictly impossible as in the case of marrying one’s own brother or father.

Effect on the Story

Well, business as usual I guess. According to these rules, practically every marriage contracted in Lothere technically requires a dispensation; not to mention that we’re so far from Rome that such rules are probably willfully ignored. (King William did.) Also, Lothere is part of the Celtic Church rather than the Roman. I don’t know what difference that makes, but at least the influence of Rome was much less here.

So my guess is that when someone noble enough to be noteworthy to the Church gets married, they apply for a dispensation the same way we would apply for a marriage license. Or better yet, they do nothing and wait to be reminded (which probably never happens), at which point they say “Oh gee we didn’t know” and pay the fee for a dispensation.

(Lord Aed and his clan follow their own inscrutable rules of course… I can only imagine the local ecclesiastics tremble in fear before him.)

Orlaith, Donnchad, and Aed.