Since ancient times, when societies were tribal, there were councils or a headman whose decisions were assessed by village elders. Eventually, these councils have slowly evolved into the modern parliamentary system.
The first parliaments date back to Europe in the Middle Ages, specifically in 1188 Alfonso IX, King of Leon (Spain) convened the three states in the Cortes of León. An early example of parliamentary government developed in today's Netherlands and Belgium during the Dutch revolt (1581), when the sovereign, legislative and executive powers were taken over by the States General of the Netherlands from the then-monarch, King Philip II of Spain. The modern concept of parliamentary government emerged in the Kingdom of Great Britain between 1707–1800 and its contemporary, the Parliamentary System in Sweden between 1721–1772.
In England, Simon de Montfort is remembered as one of the fathers of representative government for holding two famous parliaments. The first, in 1258, stripped the King of unlimited authority and the second, in 1265, included ordinary citizens from the towns. Later, in the 17th century, the Parliament of England pioneered some of the ideas and systems of liberal democracy culminating in the Glorious Revolution and passage of the Bill of Rights 1689.
In the Kingdom of Great Britain, the monarch, in theory, chaired cabinet and chose ministers. In practice, King George I's inability to speak English led the responsibility for chairing cabinet to go to the leading minister, literally the prime or first minister, Robert Walpole. The gradual democratisation of parliament with the broadening of the voting franchise increased parliament's role in controlling government, and in deciding who the king could ask to form a government. By the nineteenth-century, the Great Reform Act of 1832 led to parliamentary dominance, with its choice invariably deciding who was prime minister and the complexion of the government.
Other countries gradually adopted what came to be called the Westminster Model of government, with an executive answerable to parliament, but exercising powers nominally vested in the head of state, in the name of the head of state. Hence the use of phrases like Her Majesty's government or His Excellency's government. Such a system became particularly prevalent in older British dominions, many of whom had their constitutions enacted by the British parliament; examples include Australia, New Zealand, Canada, the Irish Free State and the Union of South Africa. Some of these parliaments evolved were reformed from, or were initially developed as distinct from their original British model: the Australian Senate, for instance, has since its inception more closely reflected the US Senate than the British House of Lords; whereas since 1950 there is no upper house in New Zealand.
Democracy and parliamentarianism became increasingly prevalent in Europe in the years after World War I, partially imposed by the democratic victors, Great Britain and France, on the defeated countries and their successors, notably Germany's Weimar Republic and the new Austrian Republic. Nineteenth-century urbanisation, the Industrial Revolution and, modernism had already fuelled the political left's struggle for democracy and parliamentarianism for a long time. In the radicalised times at the end of World War I, democratic reforms were often seen as a means to counter popular revolutionary currents.