When I was about 11 I read Even More Terrible Tudors, from the Horrible Histories series by Terry Deary. In fact, I read it repeatedly, until it was borrowed and lost by my cousin. I learnt a whole lot of things from this, most relevantly that Queen Mary I of England was married to King Philip II of Spain. I knew that her father, Henry VIII, had a string of wives, but not until more recently when I saw The Other Boleyn Girl did I properly realise which one was Mary’s mother – his first wife, Catherine of Aragon. This is interesting because Aragon is in Spain. So I could only assume that Mary’s mother and husband were somehow related to each other.
As it turns out, they were. I’ve made a family tree to illustrate:
The deal here is basically that Philip II was Catherine’s sister’s son’s son – that is, her grand-nephew. The rules for labeling relatives can be confusing but this makes Mary and Philip II first cousins, once removed. (Mary and Philip’s father Charles were first cousins, and Philip being one generation further down from this adds the “once removed” part.) So that is the answer to the question posed in the title – how related were Mary I and Philip II? First cousins, once removed. If you were worrying about inbreeding, you may be pleased to know that they didn’t have children (though not for lack of trying, apparently).
This was not an unusual degree of relatedness for noble marriages at the time. For a while when she was a child, it had actually been arranged for Mary to marry Philip’s father Charles, her first cousin. Twelve years after Mary died, Philip went on to marry his niece, Anna of Austria.
Next question: why was Mary’s mother Catherine of Aragon and not Catherine of Spain? The reason is that Spain didn’t exist until Catherine was 30. Her parents jointly ruled over most of what is now Spain, but it wasn’t actually a single crown until Ferdinand died and Joanna, having already inherited the throne of Castile from her mother, was able to sidle across to half-sit on the throne of Aragon as well, becoming Queen of Spain in 1515. (Although her son Charles, taking over the job of Regent from his grandfather, who had taken over from Philip I, did most of the actual ruling. A Regent was seen as necessary because Joanna was apparently insane, though whether it was really just that her relatives wanted to be in charge is up for debate. It also brings up another interesting point, which is how irritating it must have been for her controlling male relatives that she lived so much longer than everyone else in the family seemed to.)
For the sake of curiosity, and while on the subject of noble relatedness, let us turn to a couple of fictional examples from The Lord of the Rings. Elrond and his wife Celebrían, Galadriel’s daughter (I often wonder if Cate Blanchett knew she was playing Liv Tyler’s grandmother), were second cousins, twice removed. More uniquely, perhaps the only example of its kind, Aragorn and Arwen were first cousins, 62 times removed. Oh, the wonders of biracial marriage!
As a final side note, Anne Boleyn’s signature appears to have been “Anne the quene.” Very concise, I like it.
Digressive Explanations 