The Instrument of Government of 1719 adopted on 21 February 1719 by the Riksdag of the Estates was one of the fundamental laws that made up the constitution of Sweden from 1719 to 1772. It came about after the succession crisis which occurred after the death of Charles XII of Sweden, when the monarch died childless during the Great Northern War, leaving two potential heirs: his sister Ulrica Eleonora of Sweden, and his nephew Charles Frederick, Duke of Holstein-Gottorp. The constitution was a result of the agreement made between Ulrica Eleonora and the Riksdag of the Estates, were the latter acknowledged her as queen regnant in exchange for signing a new constitution of reduced royal power and introduction of a parliamentarian system. The Instrument of Government of 1719 was only revised to a very small extent in the following Instrument of Government (1720), and it can therefore said to be in effect during the entire age of liberty, and represent the political system in Sweden until the Swedish Constitution of 1772.