I am talking about how, in the medival times, everything was controlled by Kings. But when and how did it stop?
This isn't to stop any further discussion or more side questions but /u/grumblingduke gave a great answer to a similar question about a year ago.
There's a discussion about what constitutes as power as since the Norman invasion, kings had constitutionally absolute power in law but they had to have political power/capital to back it up or a powerful group of barons lords uppercrust types would take over to dilute the powers the monarchy had or place themselves at the top.
After the Glorious Revolution, the many powers of British monarchy were moved to Parliament in the bill of rights the newly installed monarchs signed. This marked the end of the right to absolute rule (but still had vast estates and powers of patronage to influence policy). Technically you could say James the 2nd who was deposed was the last absolute ruler but later kings still had power of patronage and could influence decisions in how the state was run.