If you’re in the north of England and you’re in a town ending in -by, you’re in former Danish-ruled territory . If the toponym starts with beau- or bel-, it was probably named by Normans . And if it contains the prefix Avon- or the suffix -combe, it is one of many place names of Celtic origin that dot the islands on this map .
Analysis of place names can be highly informative of the languages historically spoken and ancient peoples once settled in any given country. The most obvious method for such an analysis is etymological. But what if we picked a more random pattern than word-origin?
UK and Ireland (A through J)
What, for example, does a purely alphabetical analysis of place names tell us? It’s highly unlikely that settlers chose the names for their villages and towns by minding the Ps, Qs or the other two dozen letters of their alphabet. But that doesn’t mean that the patterns are completely random - just that there’s one more level of encryption between the pattern and its reader.
Take this series of 26 maps, each showing the density and distribution of British and Irish toponyms starting with each of the letters of the modern alphabet. Some observations:
UK and Ireland (K through T)
- There doesn’t seem to be a single location within the British Isles  that has a name starting with X. What, not a single stately pleasure-dome named after Kubla Khan’s Xanadu ?
- The six Incidences of Z, the rarest actual toponymic initial, are mainly concentrated in the southeast of England: Zeals in Wiltshire, Zeal Monachorum in Devon and Zennor, Zelah and Zone Point (almost certainly Zoze Point, probably miscorrected) in Cornwall. Why this cluster? There doesn’t seem to be an etymological link. Intriguingly, as if to throw off a scent, the sixth Z is way up north: Zetland, a variant to Shetland .
- Other rare, but less infrequent initials: J (almost all in Ireland and the Celtif Fringe of Great Britain), Q (surprisingly frequent, actually), V (hot spots on the Hebrides and on Shetland) and Y (mainly southern, and very Welsh).
- Of the medially frequent initials, A is remarkable for dominating in the Scottish Highlands; D and K seem to be most at home on either side of the Irish Sea, in Scotland and Ireland; I is a chiefly Scottish affair (all those Inver- prefixes?), and L rules supreme in Wales (which I guess is down to all those places starting with Ll- ).
- Of the very frequent initials, B and C are most popular across large swathes of Ireland; and H, S and W are dominantly English.
UK and Ireland (U through Z)
Many thanks to Mukund Unavane for sending in these maps, all 26 of his making (and located here), based on the data publicly available from the GEOnet Name Server (GNS) at the National Geopspatial-Intelligence Agency (NGA).
 As in Grimsby, Wragby or Haxby. ‘By’ (pronounced bee) is still the Danish word for ‘town’. Other originally Danish suffixes: -sted (Stansted), -thorpe (Scunthorpe), -toft (Lowestoft).
 Normans often renamed places they didn’t like the sound of, such as Fulepet (‘Filthy Hole’) in Essex, which became Beaumont (‘Fairhill’), or Merdegrave in Leicestershire, which was turned into Belgrave.
 e.g. Ilfracombe; the suffix still gives a good indication on how to pronounce its Welsh equivalent cwm, which also means ‘valley’.
 For earlier discussions on whether Ireland is or isn’t a ‘British’ island, see the posts and comments at #196, #514 and #535. My current opinion: like language in general, geographical nomenclature is subject to consensus, hence to change. So while ‘British Isles’ has the advantage of brevity (and some support in etymology), ‘British and Irish Isles’ is a perfectly acceptable alternative - if and when accepted by enough language users.
 See the poem Kubla Khan (1797) by Samuel Taylor Coleridge.
 Not on this map (at least not visibly), but mentioned by GEOnet.
 Perhaps most famously Llareggub, the (fictional) setting for Dylan Thomas’s Under Milk Wood. If you want to know where he got the name, reverse it.