Just a quick post to say congratulations to the Duke and Duchess of Cambridge on the birth of their son yesterday afternoon. His birth means that the system of primogeniture has actually been somewhat irrelevant in Britain for several generations. The prince's father and grandfather are, of course, their parents' eldest children (not just their eldest sons). The current queen had no brothers, while her uncle (Edward VIII) and father (George VI) were the eldest two children of George V (the eldest surviving child of Edward VII. In fact, only Edward VII would have lost out, with his elder sister, Victoria, taking the crown instead.
While, in the UK, legislation is now in place (but not in force) to end primogeniture, it is only a matter of time before girls have inheritance rights equal to their brothers. Since there appear to be a few difficulties to iron out before the change can be fully made however it is perhaps no bad thing that the little prince is not a little princess!