How far from the truth tales can wonder, it started in 1694, and has been modified and enhanced ever since. In 1794 a number of taxes were clumped together, as moneys needed to be raised to fund a war against a despot….Napolian! So, taxes were paid to the crown, to defend the people and country. So, basically if you apply taxes the to monarchy your asking them to pay for their own services is a nutshell. We the people transferred the power, the taxes and the responsibility to the elected Government, but the crown is still the leader of all the armed forces. Ie they lead us into battle.
Very simplified.