There was only one monarch executed in British history, and it was also the first monarch executed in European history. He is Charles I of the Stuart dynasty in England.

In A.D. 1642, Charles I and his royalists finally broke out with the British Parliament and its bourgeoisie, which was the famous English Civil War. The civil war lasted for five years in a small area of England. The two sides attacked and defended many times, and the balance of victory always swayed to both sides. It was not until A.D. 1647 that the parliamentary army finally defeated the royalist army and captured Charles I alive.

In A.D. 1649, Charles I was publicly executed by the British on the guillotine. He died at the age of 49 and reigned for 24 years. He was the only monarch executed in British history and the first monarch executed in European history.