Political and religious reasons
For the king: Pym was too extreme with impeaching the queen, becomming puritan, abolishing bishops. Didn't want Parliament to choose commander - the militia bill. Triennal act was passed so they were happy. Strafford killling too far. 10 propositions meant parliament were trying to take control. Star chamber was abolished and no more ship money so they were happy. Gentry didn't want the peasants and yoemen to be in charge, still valued class heirachy.
For Parliament: The king had too much power, the illegal finance measures of personal rule. Didn't want another personal rule. Didn;t want two capital cities, he moved to york. Thought Charles was plotting against them in Scotland 1641 and with papists in Ireland. Fear of other tyrannical advisors such as Strafford and Laud.
Religion For the King: Thought Pym would change the religion to Puritan. Didn't agree with Pym's Root and branch bill too extreme too much power to priests. Laud in the tower so less Arminian influence. Subjects should obey the kings religion due to divine right. Thought the king had done enough concessions.
Religion for Parliament: The king was too Arminian - changing religion. The queen was catholic and went to get catholic troops from france to help the king. Catholic plot in ireland supported by king. Didn't like changes in the church. They wanted more concessions. Wanted to defend 'ancient and traditional rights' which had been 'violated by abitary rule'. Arminians were drunk, swore, fornicated and were adulterous, puritanism was more focused on sermans and order.
- Some people chose their side due to what the gentry in their county were supporting (Prism of Localism). Most yoemen and peasants were illiterate and didn't really understand what was happening in parliament however some did understand the questions of constitutional debate. Nottinghamshire the earl of newcastle had a lot of influence and was for the king so most of the county followed him.
- Cheshire, kent, Staffordshire and some of Yorkshire were neutral. Where happy to fight either army to keep their county neutral though. Armies put pressue on neutral counties. If either army was occupying a county that county usually sided with them due to force 'had no other alternative' as with Leicestershire which was divided between royalist Hastings and Puritan Grey, or like somerset just supported which army was most powerful at the time
-Buckinghamshire supported the king due to honour and tradition, almost whole county behind them. fear of parliaments constitutional innovations, religious radicalism and popular rebellion. Not to do with the bad economy as in Yorkshire 3/4 of the people in financial decay went with the king. However, bad economy did pursuade some to go with Parliament.
- religion was a bit part in side taking. Suffolk and some of Yorkshire was against the king, they wanted to get rid of popish remnants in church and begin spiritual reform, wanted to get rid of drunkenness, swearing, fornication, adultery and other sins, which is why most people didn't like the royalists. Joining Parliament meant religious purity. 90% of catholics became Royalists, 72% of puritans became parliamentarians.
Parliament puritanism stressed moral reformation, individualism and the ethic of work and responsibility. Royalist Arminianism stressed cutsom, tradition and the co-operative 'vertical' community.
Size of armies waxed and waned depending according to the hardships of service and how much money they had to offer to the soldiers. Shows that people joined partially for partisan enthusiasm and partialy for the money.
very few people left statements of any sort which made explicit their reasons for engaging in the conflict.
Somerset - most with king, low classes that gained money were angry that they didnt have same reputation and esteem joined P. Also drifted with the tide of who was more powerful at the time.
Sir Simonds D'ewes. suffolk against the KIng as wanted 'religious purity' and spiritual reformation, 'reformation of manners'. Arminians drunken and adulterous and other sins.
Yorkshire - 240/680 gentry remained neutral. 90% catholics, 72% puritans.
Nottinghamshire - Fought for King as Earl of Newcastle's family very influential and hugely loved.
Buckinghamshire - Edmund Verney fought for king for 'sense of honour and tradition'
Fenlands - Commoners oblivious to constitutional debates meant they could regain commons.
Lancashire - Forceful Royalist army, had no choice