Popular monarchy is a system of monarchical governance in which the monarch's title is linked with a popular mandate rather than a constitutional state. It was the norm in some places (such as Scotland) from the Middle Ages, and was occasionally used in 19th- and 20th-century Europe, often reflecting the results of a populistrevolution. Thus during the French RevolutionLouis XVI had to change his title to indicate he was the monarch of the people rather than sovereign ruler of the land.
Currently, Belgium has the only explicit popular monarchy. Constitutional monarchy in the modern sense can be considered an evolution of the idea, as such constitutions generally place sovereignty with the people, not the monarch.
The first Portuguese king, Afonso Henriques, used the style King of the Portuguese (Rex Portugalensium), to remember that he was elected on the battlefield, after the Battle of Ourique (1139), by his fellows and subjects; their descendants, instead, used the style of King of Portugal (Rex Portugaliae or later in Portuguese: Rei de Portugal).
Used by Zog I, the one ruler of the Kingdom of Albania, from 1928 de facto to 1939, and de jure until 1946. Victor Emmanuel III, who claimed the Albanian throne between 1939 and 1943, used the title "King of Albania."
This usage became less common with William and Mary, who chose to be called King and Queen of Scotland. The Act of Union 1707 abolished the Scottish and English thrones and created the Kingdom of Great Britain.
Evolving from King of the Britons, before mediatising in the 12th century as Prince of the Welsh. Eventually, Dafydd II of Gwynedd and Wales adopted the title Prince of Wales to denote suzerainty over the whole of Wales, not just the Welsh people.
The official title of Ferdinand I in 1908-1918, Ferdinand's son Boris III (1918-1943) and Boris' son Simeon II (1943 - at least to 1946) was: by the Grace of God and the People's Will King of the Bulgarians. In fact, Ferdinand I was elected by the National Assembly as a Prince of Bulgaria in 1887.