Official Cockneys are becoming an endangered species because rising noise levels in London are drowning out the sound of the Bow Bells.
Traditionally a Londoner must be born within earshot of the bells to be a true Cockney, but their range is reducing.
Glen Goodman found out more.
The first Diamond Jubilee river rehearsal of the bell ringers on the Belfry barge has taken place on the Thames. The barge will lead the Queen's Jubilee flotilla and carries eight church bells which will peel out across London as the procession makes its way up the Thames.