Writing about Cromwell's head got me to thinking about severed heads in general (as you do). The obvious link is to Charles I, the king whose head Cromwell was instrumental in removing (and thereby causing the later post-mortem severing of his own).
Charles I was executed on a black-draped scaffold erected outside the Banqueting House, whose amazing Rubens ceiling I saw for the first time last year when the New Statesman held it's summer party there. When his head was lopped off, bystanders rushed forward to dip their handkerchiefs in the blood as a memento.
Charles' head was lopped off in one go, which is more than can be said for Mary Stuart - Mary Queen of Scots. The executioner managed to hit the back of her head with the first blow and only severed her head on the third. He held up the head with a cry of 'God Save the Queen' only to find that her auburn curls were a wig. The balding head slipped from his grasp and bounced across the floor towards the audience.
Jack Ketch (who gave his hated name to all executioners) was horribly incompetent. The Duke of Monmouth gave him six guineas to do a good job when he was to be executed, but he also felt the axe and raised concerns about whether it was sharp enough. He may have had a point. Ketch's first go simply wounded the Duke. Two more goes and the head still wasn't severed. Ketch threw down the axe and said he couldn't carry on. Ketch was forced to continue amid boos, had two more goes and finished the job like a butcher with a knife, narrowly avoiding being lynched by the crowd.
Sir Walter Raleigh worked the crowd at his execution for three quarters of an hour. When he was shown the axe he said, 'This is a sharp medicine but it is a physician for all diseases' and when the axeman faltered said, 'Strike, man, strike!' As with Mary Stuart, onlookers noticed his lips were still moving as the head tumbled to the floor. The head was put in a velvet bag and Raleigh's wife, Bess, had it embalmed and kept in a special case.