Geographical spread of surnames

Sometimes I listen to radio 2 in the car on the way home, why?, cos i can't get 6 music and scott mills is annoying. So excuses out of the way, (actually maybe it's because listening to steve wright in the afternoon reminds me of my teenage years listening to him at this time on radio one or one fm or whatever it was called those days) tyhey have a feature called website of the day. On monday they spoke about an interesting site where you could track the geographical density of a surname. The site used data from a census in 1881 and the electoral role of 1998 to calculate these densities. It is interesting comparing the two maps. I've learnt that Iddon has a frequency of 27 in every million people. As I knew the name is localised in the north west around lancashire, and by 1998 had spread, most notably to the area around Durham. People of my great grandfather's generation migrated here to work down the coal mines and my own grandad originally came from this area. There is striking localisation of most names, which demonstrates how little migration has really occured in the last 100 years, and there is a very striking north/south divide too. This probably derives from the ancient anglo and saxon kingdoms that probably had slightly different dialects and therefore names.

Should you wish to check out your name, the site is here