The three British civil wars pitted brother against brother, ripped families and communities apart – and resulted in more than five per cent of the total population of England, Scotland, Ireland and Wales being slaughtered. Relations between the King and Parliament had been deteriorating since the rule of King James the First. When he died in 1625, and Charles, his eldest surviving son, became King, relations between the crown and the people dipped to a new low. But rather than listen to the voice of Parliament, the King believed he was only answerable to God. This meant the people were expected to bow to his will. A succession of domestic and foreign disasters – such as the levying of the hugely unpopular 'Ship Money', the imposition of 'popist' religious practices on the Scottish church and several embarrassing and costly  military failures – left the King and Parliament at loggerheads with one another. 
Neither would yield any ground to the other side. By 1642, matters had become so bad there could only be one outcome: armed conflict.
Civil war was declared on 22 August 1642, when the King raised his standard in Nottingham. Nine years of bloody warfare ensued, during which time Charles lost his throne and head; Oliver Cromwell became the most powerful commoner in British history; and Francis Hacker – a Leicestershire landowner and gentleman – rose from obscurity to be become one of the New Model Army's finest commanders.