let a simpleton educate you northerners
To be a Cockney, you have to be born within the sound of the Bow Bells, within ear shot.
the Bow Bells are situated in Central London, Cheapside to be exact, not all Londoners are Cockneys.
Whitechapel, Stepney, Bermondsey, some parts of Hackney etc. Cockneys.
In football terms the only Cockneys are Millwall, not even West Ham are Cockneys.
Google is the place to look for the history of it all.
Es***red52.