A parliamentary system, or parliamentary democracy, is a system of democratic government where the head of government derives their democratic legitimacy from their ability to command the support ("confidence") of the legislature, typically a parliament, to which they are accountable.

In Swedish and Finnish history, the Age of Liberty was a period that saw parliamentary governance, increasing civil rights, and the decline of the Swedish Empire that began with the adoption of the Instrument of Government in 1719 and ended with Gustav III's self-coup in 1772. This shift of power from the monarch to parliament was a direct effect of the Great Northern War.