- Half — A half relative is someone who shares half of their normal relatedness with you due to a remarriage or birth out of wedlock. Thus, where a brother could hypothetically share 100% of your genes, a half brother couldn't share more than 50% because you have a different parent (it could be a father or mother, doesn't matter). Usually, only siblings are designated as halfs, although aunts and uncles can also be half (they are your father or mother's half-sibling). Cousins can only be half if your aunt or uncle is a half relative (in fact, the entire descent of that half-uncle or half-aunt are half-cousins). You can never have a half-parent or a half-child.
- Step — A step-relative is either someone who shares none of their normal relatedness with you due to being the offspring of an ancestor's previous pairing or a person who is not biologically related to you but has married your ancestor. For all intent and purposes, a step-relative is not a relative at all and people throughout history have often married and/or bred with their half siblings. A great example of this is the ever-famous Brady Bunch. The family was composed of a father who had three boys from a previous marriage and a mother who had three girls from a previous marriage, who then got married and everyone had to live together. Part of the tension in a few select episodes was due to the fact that the children could hypothetically hook up. This same vein has been used in hundreds, if not thousands, of film plots where children hook up then hook their parents up, or vice versa. Virtually anyone can be a step-relative. All you need is to have at some point an ancestor remarrying with someone who already has kids. Step relationships have played an important and sometimes dangerous part in royal politics through the centuries.
|The Brady Bunch|
Now to return to a more serious note, why are these relationships so important to dynastology? It's because many succession disputes began between children of multiple marriages. We'll start with my example above. Mary Tudor was the daughter of Henry VIII and Catherine of Aragon, and was raised a proper Catholic. Elizabeth Tudor was the daughter of Henry VIII and Anne Boleyn, and was raised a Protestant. Jane was the eldest daughter of Francis, the eldest daughter of Mary Tudor, the sister of Henry VIII and was also raised a Protestant. Now that we have our three major players, let's see what happened when Edward VI died in 1553:
|Mary I, Queen of England 1553 – 1558|
|Elizabeth I, Queen of England 1558 – 1603|
Mary, since she was Catholic, was declared unfit to succeed while Elizabeth, who had previously been declared illegitimate since divorce was sort of frowned upon back then, was skipped because of her possible illegitimacy. Jane, therefore, was the next in line to succeed since the will of Henry VIII had clearly set the line of his younger sister Mary Tudor first since his elder sister Margaret was married to the King of Scotland. The problem was that Mary Tudor wasn't illegitimate and there were in fact no laws barring Catholics from the throne at the time. Furthermore, according to the Church of England, which Edward and Jane supported, divorce was perfectly legal and therefore Elizabeth wasn't barred either. So Mary Tudor tromped into London and took over from Jane who was executed a short year later. Elizabeth succeeded Mary a few years after that. Thus half-siblings managed to work things out in the fact of worse alternatives.
|Emperor Romanus IV and Empress Eudokia of Byzantium|
Step and half relationships have shown themselves across royal family trees to be both dangerous and advantageous. Sometimes, a step-child may be the only thing that holds a dynasty together. Other times, though, the proximity to power may be too close for comfort.