On the 3rd of October 1283 Dafydd ap Gruffydd, Prince of Gwynedd, Wales was executed on the orders of Edward I of England.

Dafydd ap Gruffydd, was the last ruler of an Independent Wales.

He was a complicated character up against the power of Edward of England who was extremely skilled at using whatever divisions and personalities he could for his aims, to completely subjugate Wales.

Dafydd ap Gruffydd was condemned on the charge of high treason against the king (that being Edward of England) and that is said to be the first use of those terms.

Dafydd was dragged through the streets of Shrewsbury attached to a horse’s tail, then hanged alive, revived, then disembowelled and his entrails burned before him for “his sacrilege in committing his crimes in the week of Christ’s passion”, and then his body cut into four-quarters “for plotting the king’s death”. Geoffrey of Shrewsbury was paid 20 shillings for carrying out the gruesome act on 3 October 1283.

Wikipedia

His head was displayed in the tower of London.