Charles I called Parliament to ask for taxes to raise money for war against the Scots. Parliament agreed to grant the King 'twelve subsidies' on the condition that 'ship money' was abolished. Ship money was a tax normally imposed at time of war to allow the King to build ships for the defence of the country, but Charles had imposed this tax in peace times without Parliament's consent which was illegal. John Pym stood up against the King and complained about how he was running the country. Charles grew impatient and dissolved Parliament on May 5, only three weeks after Parliament was called.
Charles I, with a small band of soldiers, attempted to arrest key leaders of Parliament including John Pym. When Charles arrived at Westminster he found that the men had already left and had found sanctuary in the city of London. Charles had little support in the city and had little choice but to leave.
Selection of references used:
1. John Kenyon, The Civil Wars of England, ISBN:0-297-79351-9
2. Maurice Ashley, The English Civil War, ISBN:0-7509-0019-9