The fundamental origins of the Civil War lay in the friction between the King and his supporters and Parliament. This confrontation was further heightened by the very marked differences in religious views between the two sides : the Anglicanism of the Royalists against the Puritanism of many of the Parliamentarians. It was brought to a head by economic, religious and political factors, and by the character of King Charles I himself.
His attempt to rule without calling a Parliament collapsed as a result of the Scots Wars of 1639 and 1640, followed by the Irish Rebellion of 1641. Parliament set out to remove their opponents from power, impose tighter controls on the Crown, and increase its power. By the beginning of 1642 the two sides were on a collision course which led inevitably to war.
The Midlands and the South of England, because of their strategic importance, containing as they did London and the Royalists' temporary capital of Oxford, saw more fighting than any other part of the country, as well as most of the larger battles.
The King raised his Standard in Nottingham on 22nd August, 1642, and the opening campaign saw the battle of Edgehill in Warwickshire (22nd October). Though tactically a draw, the engagement left King Charles free to continue his march to London, until he was halted at Turnham Green, on the outskirts of the capital. A temporary Royalist capital was established at Oxford, which was strongly fortified and further protected by a system of garrisons. During the next few years, the area surrounding Oxford was the focal pointof many military operations.