We now have quite detailed information on the numbers of ancient oaks in the UK as well as in many other European countries. Numerous people have been measuring these trees and compiling lists and in recent years much of this information has been put on the Internet in various websites. Not all countries have been surveyed equally well and in some there is still a lack of good recorders, yet they have been visited by foreign enthusiasts. Certainly for the biggest oaks we can now compare the numbers by country.
The really big oaks are those with a circumference (girth) of more than 9.00 m. The very biggest are from 12.00 m to 14.00 m and these can almost be counted on the fingers of two hands in all of Europe. There are 11 oaks of that enormous size in Europe: 1 in France, 1 in Germany, 1 in Spain, 1 in Sweden and... 7 in England. In England, there are 115 living ancient oaks >9.00 m and in the rest of Europe (that includes Scotland and Wales) only 98. For oaks of smaller girths the data may be less complete in some countries. Even in England we can still find surprises; in the winter of 2013 I recorded an ancient oak in a remote corner of Blenheim Park measuring 10.37 m that was new to the list of the Ancient Tree Inventory database of the Woodland Trust. It is now also the biggest oak in Oxfordshire. So even when more big oaks are found in Europe, which is almost certain, England is likely to maintain its lead over all other countries combined.
The current dataset I am working with has about 3,320 ancient and veteran oaks with girths from 6.00 m to the maximum, counting only oaks in England. This figure may also beat the rest of Europe, but we cannot be entirely sure of that.