Death bed literally refers to the bed someone dies in, however it is more commonly used in the field of history to describe some action taken before death, mainly of a religious nature.
Notable Uses Edit
Charles II, King of England : Death Bed Conversion
Died on the 6th February 1685 at Whitehall Palace. Converted to Roman Catholicism on his death bed and is reported to have told his brother, the Duke of York, to "let not poor Nelly starve" - Nelly being Nell Gwynn, his last mistress.
Charles Darwin, Naturalist : Death Bed Repentance
Died on the 19th April 1882 at his home in Downe, Kent. Is alledged to have recanted his life's work and ask for forgiveness from God for disproving creationism. This has yet to be proved.
Elizabeth I, Queen of England : Death Bed Succession
Died on the 21st March 1603. She apparantly silently mouthed to Robert Cecil that her cousin, the Scottish King James, should become King of England upon her death. Other accounts of her death claim that she actually said aloud, "Who could that be but my cousin Scotland?" when asked who would succeed her.