So I was watching the third season of “Todd Margaret” and the thing that leapt out at me as an error: There’s a Lord Mountford (the series takes place in London), and Mountford’s son is referred to as “Dave Mountford.” Is that likely? I’m an American*, but I thought that nobles’ names and titles weren’t the same. Lord Byron’s name was George Gordon, after all, and Lord Kelvin’s name was William Thompson - but I don’t know if those two cases are representative. Anyone know?
and Americans are notorious for not understanding how titles work (I’ve heard of American teachers thinking that “George Gordon” was the name of Byron’s collaborator, and in an English mystery I read once, an American thinks poorly of a noble because when they met in Paris the noble was using a different name than he uses in London (in Paris he uses his name, while his friends in London call him by his title).
Lord Mountford could be a life peer. For most life peers, the title name is the family name - e.g. Baroness Thatcher. Baroness Thatcher’s children, naturally, have the surname “Thatcher”.
Lord Mountford could be a hereditary peer, but have the family name as his peerage title. This isn’t unknown - e.g. Earl Spencer, the father of Lady Diana Spencer.
Lord Mountford could have the family name of (say) Smith, but be the Earl of Mountford, socially called Lord Mountford. He could also have a subsidiary title, which could be Viscount Mountford and, by convention, that title could be used as a courtesy title by his eldest son, who would then be known socially as David Mountford, not David Smith. (In that situation David Mountford’s younger brother Edward would be Edward Smith.)
There are some hereditary peerages where the title is the same as the family name. One you may have heard of is the Spencers. Note that Charles is the 9th Earl Spencer, not the 9th Earl of Spencer.
That’s actually exceptionally unlikely. Indeed, I rather suspect that there has been no such case in Britain in recent centuries. Why? Because having the heir use a courtesy title that is so similar to that held by the peer to whom they are the heir would be incredibly confusing. Of course, there are plenty of cases where a peer’s second most senior title is the same as his most senior, because they preferred to use the same placename or their surname when promoted to the more senior rank. But in such cases it was trivially easy for the monarch also to grant them a completely different title at their previous rank, so that the heir can use a different courtesy title.
Once again, the Spencers provide a neat illustration of this. When John Spencer, 1st Viscount Spencer, was promoted to become 1st Earl Spencer, he was also created Viscount Althorp. That made no difference whatsoever to him as he was already a viscount and, anyway, he had now become a earl. It did however make a big difference to his son, as he thus got a separate courtesy title. The Althorp viscountcy was created solely to avoid any confusion. There have been many other cases where the same issue has arisen. Each time that same simple solution has been adopted.
Although a few never got one, so their heirs traditionally use entirely fictitious titles. The heir apparent to the earldom of Guildford, for example, is traditionally “Lord North” even though the barony of North hasn’t been held by the Earl of Guildford since the 18th century.
Just to be helpful: Althorp is a village in Northamptonshire where the family home (Althorp House) is. The name of Althorp House, below, is now pronounced AWL-thorp – not AWL-trupp, as it has been for who knows how many centuries – by order of Earl Spencer, whose estate it is.
Wouldn’t want any visitors to make fools of themselves now, would we.
And, probably not relevant in this case but interesting none the less, you have the current children of the Prince of Wales going by the names William Wales and Henry/Harry Wales in their professional lives in the military (until Will became Duke of Cambridge). Wales clearly isn’t their actual surname, just the most important title that their father holds.
More recently when the former King Edward VII was created Duke of Windsor after his abdication no subsidiary titles were created. It was a moot point anyway since he & Wallis never had any kids and the title when extinct when he died.