Power: Constitutional Monarchy Britain had a constitutional monarchy in 1783. Power is shared between Parliament and the Crown. Parliament was in charge of laws, taxes, spending and debating on subjects of importance at a national and local level. The Monarch was head of state and retain several important powers, however, they could not rule without parliament and as such their powers where limited. Most political power rested with the HoL though the power of the HoC was waxing. Prime Minister was increasingly reliant on parliament rather than the monarch.