Althorp – pronounced ‘Awltrup’** pronounced ‘Awl-throp’, ‘Awl-thrup’ or occasionally ‘Awl-thorp’, actually. And you misspelt it, it’s ‘Althorpe‘.
Belvoir – pronounced ‘Beever’** can be pronounced ‘Beever’ in some dialects but ‘Bel-vwar’ or ‘Bel-vwah’ is more common.
Cholmondely – ‘Chumli’** ‘Chum-lee’, I might have heard, but ‘Chum-on-lee’ is the pronunciation.
Featherstonehaugh – ‘Fanshaw’** Nope, you pronounce it ‘Feh-thur-stowne-haw’ properly. You may have heard ‘Fans-haw’ as we all shorten what we say. See below.* ‘Greenhaugh‘ is pronounced ‘Gree-hn-ahl-sh’, also.
Leicester – ‘Lester’ Yep, pretty much. (‘Leh-hstuhr’)
Leominster – ‘Lemster’ ‘Low-minster’ and ‘Leh-mis-ter’ (the latter regional to somewhere down South) are the pronunciations. ‘Lem-ster’ is, again, just shortening it; but I’m sure you’ll find someone saying ‘Lee-oh-minster’
Leveson-Gower – ‘Loosen-Gaw’** ‘Lev-ee-sun Goh-wher’ and ‘Lev-eh-sun Goh-wher’ are the proper pronunciations, this is one that everyone everywhere pronounces differently. Good luck. As a surname one may pronounce it as you’ve said.
Magdalen – ‘Maudlin’** British = Mary Magdalen, pronounced ‘Maer-ee Mag-deh-lin’, but the Scottish will sometimes say ‘Mau-ad-lin’ for ‘Magdalen‘.
Mainwaring – ‘Mannering’** You’re confused. There’s the place Mannering, pronounced how it’s spelt, and Mainwaring, the surname that comes from ‘Angler’ and pronounced ‘Mannery’ or ‘Mannering’ with a short ‘ing’. See here.
Marjoribanks – ‘Marchbanks’** Spelt like you’ve picked a name; Margery Banks. It’s pronounced ‘Mahrsh-bahncks’ actually. Properly I think it might be ‘Mahr-o’er-ee-bahncks’ but I don’t know. This and ‘Featherstonehaugh‘ are interesting, see below.*
Ralph – ‘Rafe’ Nope, Ralph is pronounce ‘Rahlf’ (how you’d expect). Some people who pronounce their name ‘Rayfe’ may spell it ‘Ralph‘ but I haven’t seen an instance of that yet. So it’s just made up. E.g. ‘Ralph Fiennes‘ = ‘Rahlf Fyhnss’ (Ralph Fines). Again, see about use as a surname below**
Ranulph – ‘Ralph’ ‘Ranulph‘ isn’t used anymore but you have it right.
St. John – ‘Sin Jin’ If short for ‘Saint John‘, then pronounced ‘Say-hnt Joh-hn’ (as you’d expect). Otherwise we are to assume you mean as a given name (as a surname would also be pronounced ‘Say-hnt Joh-hn’) for which, as the person (99,999,999,999.9r times in a trillion) is not a Saint, cannot be pronounced that way, and so we sound out ‘Sihn-Juhn’ (Sin Jun, not Sin Jin). The same goes for all given names that are ‘St. [something]’.
Towcester – ‘Toaster’ (actually, this I can understand) pronounced ‘Tohw-stuhr’ but yep again.
Woolfardisworthy – ‘Woolseri’** See below* and check out links for other pronunciations.
Wriothesley – ‘Roxli’** ” “* ” “
*The great "how did it end up pronounced like that?" bit. Well, it's not really confusing to me, but I'm British. Here's some other website explaining to you that we, firstly, gave it a proper English pronunciation (as strange as Gaelic, some may say) then foreigners conquered nearly everywhere and messed it up and then we all talk fast and stuff (so, for example, 'London' becomes something like 'Luh'n') and drop letters ('hill' to 'ill' etc.) and have different dialects (in Birmingham ('Brummy'), and to some respect Liverpool ('Scouse'), 'nine' is pronounced as if it were German ('neun' pronounced 'noy-hn') with the exception that the vowel is dragged out much more ('noy-yhn') and may sound a bit like the word 'noun'.). In some instances there would be one posh person who ended up with that name through ancestry (and possibly evil relatives who wanted to make life hard) and just didn't think of how to pronounce it but by shortening the sounds. There'd also be all their servants who wouldn't have a clue how to say it (or maybe they only ever heard their master say it and never saw it written) but the spelling would remain. Yahoo! Answers; Wikipedia with a long and pretty comprehensive list***; **One may, with a surname(**), pronounce it far differently. The way I've given is a generic way, so locations, for general usage and, simply, as a word. So, if in an individual case it is a separate surname pronounced figuratively, do tell. Especially posh ones. ***This is not just of surnames, but also of locations etc. For locations (and if you read phonetics), see Wikipedia. Here is a clever chap going about giving more odd pronunciations (I'm sure in English there's another 'o' in that...) About Antimoon Post: Can we just say that they're pretty much all wrong or you've taken the word as the surname of an Aristocrat who wants to pronounce their name funny instead of, for example, as the place. As place names they are pronounced quite normally (most of the time) but Earls ('Erh-hl[s]') and Viscounts ('Vih-cow-hnt[s]') and Barons ('Bah-hruhn[s]') and Marquises ('Mahr-kheeees') all like to confuse foreigners. A lot.