For example, McDowell, or McDonald, or McKenna, etc. Is it necessary to capitalize that letter following "Mc"? And if yes, why is this so?

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    Related: Etymology for Mc and O' in names
    – RegDwigнt
    Commented Jun 10, 2011 at 23:00
  • The same goes for "De" and "Di" in Italian and "de" in Hispanic surnames: the following letter is capitalized. (Though, from what I've seen, there is a mandatory space after "de" in Hispanic names, and an optional space after "De" or "Di" in Italian names.) Commented Jun 11, 2011 at 4:05
  • I've come across the name Maconochie. I know nothing about it, except that it seems to be a Scottish surname, and that it's apparently never spelt MacOnochie.
    – user25910
    Commented Sep 10, 2012 at 18:20
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    The general rule in English is you spell people's names exactly how they tell you to spell them, whether or not that seems consistent with any pattern you've ever seen.
    – zwol
    Commented Jun 30, 2016 at 1:55

3 Answers 3


As Etymology for Mc and O' in names says, Mc is an abbreviation for Mac, and Mac is a Gaelic term meaning "son of". Hence the name McKenna means "son of Kenna", and since Kenna is a proper name, it is capitalized, even when combined with Mac.

(Of course "mac" alone is itself not a proper name, and from one view wouldn't need to be capitalized. However since it is taken as beginning the whole surname, it is capitalized as the initial letter of a proper name. In this respect, it is treated like English most often treats other borrowed prepositions in names, such as de from French and van from Dutch.)

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    Strangely enough, it's rare to see the Norman Fitz- treated this way: It's Fitzroy, Fitzclarence, Fitzsimmons.
    – Uticensis
    Commented Jun 11, 2011 at 0:27
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    Correction: "Mac" just means "son". The "of" comes from changing the nominative Diarmaid into genitive Diarmada (and then Anglicizing the heck out of it to get McDermot or something).
    – Marthaª
    Commented Jun 11, 2011 at 0:29
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    Or, for McKenna: the starting name was probably something like Cináed or Cionaodh, which becomes Cionaodha in the genitive, and then the English get ahold of it and it becomes unrecognizable. (But eminently more pronounceable.)
    – Marthaª
    Commented Jun 11, 2011 at 0:39
  • Re: Fitz - It being a mark of (acknowledged) bastardy might have a little something to do with the diminution of the father's name.
    – bye
    Commented Oct 1, 2014 at 18:38
  • When writing in Gaelic (Irish), girls' names are written with Nic or Úi instead of Mc or O as they mean "daughter" instead of "son". So that, technically, daughters and sons have slightly different surnames. The English version of the name uses Mc/Mac for everybody though. Commented Dec 16, 2015 at 10:01

It depends in part on where the person comes from. In Scottish names, the second capital is almost always correct - McDonald, MacDonald, etc (but note that 'Machinery' does need a capital H).

In names of Irish descent, sometimes the owners insist on no second capital; I had a colleague whose surname was Macdonald and he was not happy when the 'd' was capitalized. I'm not sure how general that is.

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    McDonald, MacDonald, and Macdonald are all separate Scottish surnames.
    – TRiG
    Commented Oct 5, 2011 at 16:54
  • Right. It has nothing to do with Eireland -- "Macdonald" is just a separate name.
    – Fattie
    Commented Aug 1, 2014 at 15:03

Some Scottish surnames do not have a capital. Some can be spelt with capital and some without. I was told by a Macintyre, that his name if spelt with the small case i, it meant that historically they were of the lower orders, but the name MacIntyre, with capial I, meant they were of the professional, or I guess landed classes. That's what he told me anyway.

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    (That sounds very dubious, just FWIW! folk etymology, sort of thing...)
    – Fattie
    Commented Aug 1, 2014 at 15:03
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    I haven't heard that before, but as a Macfarlane I'm disinclined to believe it... Commented Aug 18, 2015 at 0:41

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