Instrument of Government (1809)

The Instrument of Government () adopted on 6 June 1809 by the Riksdag of the Estates and King Charles XIII was one of the fundamental laws that made up the constitution of Sweden from 1809 to the end of 1974. The law came about after the Coup of 1809, when the disastrous outcome in the Finnish War led Swedish nobles and parts of the Army to revolt, forcing King Gustav IV Adolf to involuntarily abdicate and go into exile. It was thus the constitution which saw Sweden transition from an absolute monarchy of the Gustavian era (established by a previous coup in 1772) into a stable, constitutional democracy adhering to the rule of law and significant civil liberties. 
Although initially coexistent with the old Riksdag of the Estates, roughly corresponding to the French Estates-General (but with four houses, the peasants being a separate estate in Sweden), it saw the advent of a United States-style bicameral legislature in 1866 which lasted until 1971. Although the 1809 Act only curtailed the powers of the king significantly, but not severely, it eventually evolved into a system largely comparable to the US Constitution, albeit with the powers of the monarchy roughly corresponding to those of the presidency, the key differences being the absence of federalism and a codified bill of rights, introduced only in the 1970s.
The Act was finally replaced by the Instrument of Government of 1974, which formally enshrined democracy and the will and equality of the people, exercised through a unicameral parliament. In this regard, the 1809 Act more closely adhered to the principles of separation of powers and dualism and remains, with 55 year between the enactment of women's suffrage in 1919 and its abolition of 1974, the most prolific constitutional arrangement of Swedish democracy.
History.
For half a century, starting with the Instrument of Government (1719), often referred to as the Age of Liberty, Sweden had enjoyed parliamentary rule under the Riksdag of the Estates, but in 1772 that was ended by a "coup d'état" perpetrated by Gustav III: the Revolution of 1772. The coup enabled Gustav III to rule as an enlightened despot. Gustav III's son, Gustav IV Adolf, succeeded him but proved a less charismatic ruler, and the change of sides of Russia in the Napoleonic wars prompted the disastrous Finnish War and the loss of Finland, settled in the Treaty of Fredrikshamn. This provided momentum for the Swedish nobility and other forces to depose the king and restore political power to the Estates.
The aged and childless brother of Gustav III, Charles XIII was made king in 1809, but he was a mere puppet in the hands of the Estates and the question of his successor had to be solved. The election, by the Riksdag of the Estates, of the French Marshal and Prince of Pontecorvo Jean-Baptiste Bernadotte in 1810, provided not only a successor, but also a vital regent and a new dynasty. The rights of Bernadotte's successors to accede to the Swedish throne were codified in an amendment to the constitution in the form of the Act of Succession (1810).
Reforms.
The Instrument of Government of 1809 replaced the Instrument of Government of 1772. It established a separation of powers between the executive branch (the king) and the legislative branch (the Riksdag of the Estates). The King and Riksdag possessed joint power over legislation (, constitutional law in articles 81-86), while the Riksdag had sole power over the budget and state incomes and expenses () including military burdens (). While the king's power was somewhat reduced compared to the enlightened absolutism of Gustav III, the new document enabled the king to take a more active role in politics than during the Age of Liberty.
Originally, ministers were politically responsible solely to the king, who appointed and dismissed them. However, they were legally responsible to the Riksdag and a special court (Riksrätten) according to a special statute and to law in general if they committed legal offences ().
As the Riksdag's authority grew, it became increasingly difficult for a government to stay in office solely with the Crown's support. This culminated in 1907, when a government was chosen that was dependent more on the confidence of the Riksdag than on that of the king. However, in 1914, when Gustaf V made a speech opposing the program of the incumbent liberal government, it resigned, and the king appointed a conservative government of civil servants responsible to him.
The liberals won a decisive victory in 1917, but Gustaf tried to appoint another conservative ministry. However, it could not garner nearly enough support in the Riksdag. It was now obvious that the king could no longer pick a government entirely of his choosing, nor could he keep it in office against the will of the Riksdag. Gustaf yielded and appointed a liberal-social democratic coalition that effectively arrogated most of the crown's political powers to itself. At that time, it was definitively established that ministers were both politically and legally responsible to the Riksdag. From then on, while ministers were still formally appointed by the king, convention required him to ensure they had the support of a majority in the Riksdag. Although the Instrument's statement that "the King alone shall govern the realm" () remained unchanged, it was understood that he was to exercise his powers through the ministers and act on their advice. As a result, the ministers did most of the actual work of governing, making Sweden a de facto parliamentary monarchy.
During the period when it was in force several important reforms took place without affecting its status. In 1866 the Four Estates were replaced by a bicameral parliament, and in 1876 the office of the Prime Minister of Sweden was introduced. In the early 20th century universal suffrage was introduced. In 1970 the parliament was transformed from a bicameral legislature to a unicameral one.
In 1975, it was replaced by a new Instrument of Government, which stripped the king of even nominal political power and made Sweden a de facto crowned republic.