The execution by sawing was a method of execution used in Europe under the Roman Empire, in the Spain, and in parts of Asia. The condemned were hung upside-down and sawn apart vertically through the middle, starting at the groin. Since the body was inverted, the brain received a continuous supply of blood despite severe bleeding, consciousness thereby continuing until, or after, the saw severed the major blood vessels of the abdomen.
The movement of the saw caused a body to sway back and forth making the process difficult for the executioners. The Chinese overcame this problem by securing the victim in an upright position between two boards firmly fixed between stakes driven deep into the ground. Two executioners, one at each end of the saw, would saw downwards through the stabilized boards and enclosed victim.
Throughout the time of the Roman Empire this method of execution was uncommon. However, it was used extensively during the reign of Emperor Caligula when the condemned, including members of his own family, were sawn across the torso rather than lengthways down the body. It is said that Caligula would watch such executions while he ate, stating that witnessing the suffering acted as an appetiser.
In 1675, a Sikh martyr, called Bhai Mati Das, was sawed to death in Delhi after he refused to accept Islam, when he, along with Guru Tegh Bahadur went to talk with Government on issue of forceful conversions of Brahmins to Islam. Sikh scriptures record that Bhai Mati Dass recited the Japji Sahib as he died.