Final answer:
During the English Civil War era, the balance of power shifted as the Parliament gained more influence and the monarchy's authority was reduced.
Step-by-step explanation:
The balance of power evolved throughout the English Civil War era. During this time, the power of the monarch was challenged by the Parliament, leading to a shift in power dynamics. The Parliament, representing the legislative branch, gained more influence, while the monarchy's authority was reduced. This period marked a turning point in the development of checks and balances between different branches of government.