Answer:
The war was caused as a result of the refusal to grant King Charles enough money to finance the military in the war against Spain and France. He however dismissed Parliament and decided to raise a loan by all means necessary. He decided to raise his own army and this was what caused the war.
It was because of the conflict between Roman Catholicism and Protestantism. King Charles I married the Roman Catholic Henrietta Maria of France which fueled the war.
