> whereas someone in 14C England, say, would not have known any other form of governance than the unchecked power of the State (strictly, the King)

The king's powers were not unchecked. People had human rights by custom and law (Magna Carter, for example), parliament controlled taxation, aristocrats had a great deal of power, the Church had a lot of power.

Nowhere near democracy, but a very different system from an unchecked dictatorship.

Edit to add: this was the system from which modern democracy slowly evolved.