Strictly speaking, a Cockney is someone who was born within the sound of Bow Bells but Cockney Rhyming Slang is something that has evolved in the East End in general since the sixteenth century.
It has come from the seamen and soldiers who used the port of London in the East End and from Gypsies who arrived in the fifteen hundreds, the Irish residents, the Jewish faction and from all the other ethnic minorities which have made up the population of the city in the past and continue to do so today.
Cockney rhyming slang has nothing to do with Dick Van Dyke! "Gor Blimey, strike a light Guvnor (exclamation)! You can knock me down with a kipper if I'm tellin' yer porkies Missus! (Golly, I'd be really surprised if you thought I was telling you porky pies (Lies) Missus)!
Up and down these bloomin' apples and pears (stairs) all day. Me plates of meat (feet) are killin' me and make no mistake! I could just knock back a nice cup of Rosy Lee (tea) or a Laugh and titter (bitter) in the rub-a-dub-dub (Public House)!Lummy, that's a fancy whistle, mate (whistle & flute, suit)!
Try making up your own sentences with our Cockney/English dictionary but don't try them out in the East End unless you like hospital food !"