It is a question that not even Google can answer: where in the world are all the other people with my name? It sounds impossible, but it can now be answered thanks to a remarkable new website launched yesterday, which enables the names of most people in the English-speaking world, and a sizeable chunk of the rest of it, to be tracked to the places they live.
Set up by geographers at University College London (UCL), the site, publicprofiler.org/worldnames, will provide a remarkable tool for tracing family history and also a powerful aid for governments to keep track of intra-national and international migrations.
The database behind the site holds 300 million names of people in 26 countries, representing a population of about a billion, or nearly a sixth of the world.
It contains 10.8 million individual surnames and 6.5 million forenames, and can pick out which of the latter are most closely associated with the former.
It covers most of Europe and the Anglophone countries, as well as Japan, India and Argentina, although much of the rest of the globe, including Africa, is so far untouched.
The site, launched at the annual conference in London of the Royal Geographical Society with the Institute of British Geographers, shows in particular how Anglo-Saxon and Celtic names have spread over the globe with the English-speaking diaspora, with the result that they are sometimes more frequent in the former colonies than they are in the country of origin.
For example, the British Prime Minister might be interested to know the commonest country for Brown is Australia, by a slight margin over Britain, although the commonest region (as the site defines it) is Scotland, where it belongs to nearly one in a hundred people.
The commonest forenames associated with Brown are Robert, James, David, John and William.
His predecessor might like to learn that the country where the surname Blair is commonest is New Zealand - well ahead of Australia, then the US, then Canada before Britain - with New Zealand's Gisborne region being the locality where the name is most frequently found.
John, Kevin, Robert, David and William are commonest forenames that go with it.
Typing in my own name, I found that McCarthy is most commonly found in Ireland, and within Ireland, in the south-west. Nothing new there.
The surprise was that the city given as the site of its greatest frequency is Barry, Glamorgan, south Wales, whereas I know for a fact that there are so many McCarthys in Cork City that if you put a message out on Radio Cork saying "Would Mr McCarthy return to collect the tombola prize he has won in O'Connor's Lounge," the Irish Army would have to be turned out to disperse the crowds.
Professor Paul Longley of UCL's Centre for Advanced Spatial Analysis, which has developed the website and the concept behind it, explained that this was one of the glitches still to be ironed out - the Irish dataset is so far only done by counties, rather than cities, so Cork City is not picked up.
But he still made high claims for the power of the system.
One of the things the website could do, he said, was "disaggregation" - that is, to separate out ethnic mixes by name, geographically, in a given area.
Thus you can pinpoint London's many ethnicities - not just white, Afro-Caribbean or Asian, as has been done in the past - you can also locate London's Greeks or its Poles.
This is already being done on an associated website, londonprofiler.org, which will show you for example, where most of London's Poles are currently living n mainly in a curving sweep to the west of the capital, centred on Ealing and Acton.
Furthermore, said Professor Longley, the data n based on electoral rolls, phone directories and mailshot listings, was much more up to date than census data (the last British census was in 2001).
"The system enables us to create very detailed maps of ethnicity, at scales from the neighbourhood to the global," he said.
"It offers us a fresh and vivid picture of the scattering of individual families across the globe. Users can find the countries, regions and settlements in which their names were originally coined, and the parts of North America and Australasia in which they are now concentrated."
- THE INDEPENDENT