Oliver Cromwell's body was exhumed and hanged at Tyburn, before being thrown, minus its head, into a common pit.

 The head was finally buried in 1960.

www.nationmaster.com/encyclopedia/Tyburn

Execution was a public spectacle, meant to act as a deterrent to crime: convicts were drawn in a cart through the streets from Newgate, and, after they were given a chance to speak to the crowd (and, it was hoped, confess their sins), they were hanged.

The convict was placed in a horse drawn cart, blindfolded, had the noose placed around his/her neck, and then the cart pulled away. Until the introduction of a sharp drop in 1783, this caused a long and painful death by strangulation (friends of the convict often helped put them out of their misery by pulling on their legs).

After the execution there were sometimes struggles for possession of the corpse between assistants to the surgeons, who wanted it for teaching anatomy, and friends of the convict, who wanted to give it a proper burial. Concern at the disorder which occurred at such scenes led to the transfer of executions in 1783 to outside Newgate Prison.

http://www.oldbaileyonline.org/history/crime/punishment.html#death

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Oranges and lemons

"Oranges and lemons" say the bells of St. Clement's
"You owe me five farthings" say the bells of St. Martin's
"When will you pay me?" say the bells of Old Bailey
"When I grow rich" say the bells of Shoreditch
"When will that be?" say the bells of Stepney
"I do not know" say the great bells of Bow
"Here comes a candle to light you to bed
Here comes a chopper to chop off your head
Chip chop chip chop - the last man's dead."

The words of the nursery rhyme are chanted by children as they play the game of 'Oranges and lemons' the end of which culminates in a child being caught between the joined arms of two others, emulating the act of chopping off their head! The reason for the sinister last three lines of the lyrics of "Oranges and lemons" are easily explained, they were added to the original rhyme, probably by children!

This addition dates to some time before 1783 when the infamous public execution gallows (the Tyburn-tree) was moved from Tyburn-gate (Marble Arch) to Newgate. This move was necessary  to reduce problems caused by the crowds, often exceeding 100,000, gathered along the execution procession route.

The 'Great Bells of Bow', or more accurately the tenor bell of St Sepulchre, had been utilised prior to 1783 to time the executions 

 As the words to the poem "Oranges and lemons" indicate the unfortunate victim would await execution on 'Death Row' and would be informed by the Bellman of St. Sepulchre by candle light 'here comes the candle to light you to bed', at midnight outside their cell , the Sunday night prior to their imminent fate, by the ringing of the 'Execution Bell' (a large hand bell)  and the recitation of the following -

All you that in the condemned hole do lie, 
Prepare you for tomorrow you shall die; 
Watch all and pray: the hour is drawing near 
That you before the Almighty must appear; 
Examine well yourselves in time repent, 
That you may not to eternal flames be sent. 
And when St. Sepulchre's Bell in the morning tolls 
The Lord above have mercy on your soul.

http://www.rhymes.org.uk/oranges_and_lemons.htm