He organized the “New Model Army” for Parliament into a disciplined fighting force. Cromwell's army defeated the Cavaliers in a series of decisive battles. By 1647, the king was in the hands of parliamentary forces.
Eventually, Parliament set up a court to put the king on trial. It condemned him to death as “a tyrant, traitor, murderer, and public enemy.” On a cold January day in 1649, Charles I stood on a scaffold surrounded by his foes. “I am a martyr of the people,” he declared. Showing no fear, the king told the executioner that he himself would give the sign for him to strike. After a brief prayer, Charles knelt and placed his neck on the block. On the agreed signal, the executioner severed the king's neck with a single stroke.
The execution sent shock waves throughout Europe. In the past, a king had occasionally been assassinated or killed in battle. But for the first time, a ruling monarch had been tried and executed by his own people. The parliamentary forces had sent a clear message that, in England, no ruler could claim absolute power and ignore the rule of law.
Oliver Cromwell led parliamentary forces in the English Civil War.
What was the result of the English Civil War?
After the execution of Charles I, the House of Commons abolished the monarchy and the House of Lords, and established the Church of England. It declared England a republic, known as the Commonwealth, under the leadership of Oliver Cromwell.
The new government faced many threats. Supporters of Charles II, the uncrowned heir to the throne, attacked England by way of Ireland and Scotland. Cromwell led forces into Ireland and brutally crushed the uprising. He then took harsh measures against the Irish Catholic majority that are still vividly remembered in that nation today. In 1652, Parliament passed a law exiling most Catholics to barren land in the west of Ireland. Any Catholic found disobeying this order could be killed on sight.
Squabbles also splintered forces within the Commonwealth. One group, called Levellers, thought that poor men should have as much say in government as the gentry, lawyers, and other leading citizens. “The poorest he that is in England hath a life to live as the greatest he,” wrote one Leveller.
Charles I was beheaded in January 1649. It was the first time a ruling monarch had been tried and executed by his own people.