Oliver Cromwell (1599-1658).
Oliver Cromwell was the only surviving son of a family of wealthy landowners in Huntingdonshire (now a district of Cambridgeshire) and became one of the most controversial figures in British history. He was a fanatical puritan and responsible for the English civil war, and he was the most important figure in the execution of King Charles I. During his school years he was staunchly anti-Catholic and heavily influenced by his teacher, Thomas Beard, who was responsible for the puritanical book called The Theatre of God's Judgement. After his education, he briefly became a Member of Parliament for Huntingdonshire but his short term was not very impressive. He became increasingly opposed to King Charles I's understanding and beliefs of Protestantism which clashed with his own puritan outlook and beliefs.
King Charles I (1600-1649) tried to impose his religious beliefs on Scotland but they were quickly rejected and the subsequent Bishop's rebellion broke out. Charles then declared war on Scotland, recalled Parliament and tried to force an increase in taxes to pay for it. Parliament refused this after being persuaded by Oliver Cromwell and shortly after, Charles forced his way into Parliament with troops intending to arrest the most rebellious MP's but they had disappeared. Parliament then decided that it was time for the king to hand over much of his royal power to them. The king was outraged and refused, and England was now on course for a civil war.
In 1644 Oliver Cromwell demonstrated his military skills and tactics at the Battle of Marston Moor and the Parliamentarians ("Roundheads") took control of northern England after defeating the Royalists. Cromwell proved that he was an inspiring leader and helped to establish the New Model Army with recruits from all social classes and backgrounds. His new army was paid regularly and new disciplines were introduced making it easier for the officers to control the troops. The Battle of Naseby came in 1645 where the Parliamentarians demonstrated their fighting skills and defeated the Royalists in one of the last major battles of the English civil War. King Charles I was placed under house arrest while Parliament decided his fate. Meanwhile, the Royalists regrouped in 1649 and joined with the rebellious Catholics in Ireland with the intention of overthrowing Parliament. Oliver Cromwell and the Parliamentarians immediately invaded Ireland and slaughtered many thousands of people. After their return to England Cromwell's forces defeated a Scottish invasion in 1651 led by King Charles I's son at the Battle of Worcester. Now, Oliver Cromwell and the Parliamentarians had full control of England. Oliver Cromwell died on September 3, 1658 of natural causes.