Well firstly we live on an island so it's hardly surprising!!
Secondly England is not a country. It is, at best, a nation. A country must have complete sovereignty over it's territory. England's territory is under the power of the Parliament of the United Kingdom and thus England is not a sovereign state, or country (and may I just say... thank the Lord, imagine the stupid things we'd get up to without the other nations keeping us in line).
If we are to have these silly little lists of "Most Populated Countries" can we ensure all participants are countries or we may as well call it "Most Populated Regions" in which case I bet England will not take the top spot as to be honest we have several distinct English regions. I'm pretty sure there will be some obscure part of Europe teeming with people knocking us off the top as well even if we went all in as one big nation.
Tomorrow's top news story "Banana is strangest shaped apple in world".