The main cause of the English Civil War (1642-1651) was a power struggle between the monarchy and Parliament over governance and authority in England. King Charles I's attempt to rule without Parliament and impose his religious and fiscal policies led to growing tensions. The king’s authoritarian approach, including the arrest of opposition members, provoked widespread resistance. Additionally, underlying social, political, and economic issues, including disputes over taxes and religious freedom, further fueled conflict. The war resulted in significant changes to the political landscape, including the eventual execution of Charles I and the establishment of the Commonwealth under Oliver Cromwell.