Drawing and quarting was considered the worst possible and most painful punishment there was.
1. Dragged on a hurdle (a wooden frame) to the place of execution (drawn).
2. Hanged by the neck, but removed before death (hanged).
3. Disembowelled, and the genitalia and entrails burned before the victim's eyes (The other organs were torn out).
4. Beheaded and the body divided into four parts (quartered).
The head and quarters were parboiled to prevent them rotting too quickly and then displayed upon the city gates as a grim warning to all.
At some point in this agonising process, the prisoner inevitably died of strangulation and/or haemorrhage and/or shock and damage to vital organs.