In the European history, monarchy was the prevalent form of government throughout the Middle Ages, only occasionally competing with communalism, notably in the case of the maritime republics and the Swiss Confederacy.
In the early modern period (1500 - 1800 CE), Republicanism became more prevalent, but monarchy still remained predominant in Europe until the end of the 19th century. After World War I, however, most European monarchies were abolished. There remain, as of 2024, twelve sovereign monarchies in Europe. Seven are kingdoms: Denmark, Norway, Sweden, the United Kingdom, Spain, the Netherlands, and Belgium. Three are principalities: Andorra, Liechtenstein, and Monaco. Finally, Luxembourg is a grand duchy and Vatican City is a theocratic, elective monarchy ruled by the pope.
The monarchies can be divided into two broad classes: premodern states and those that gained their independence during or immediately after the Napoleonic Wars. Denmark, Norway, Sweden, the UK, Spain, and Andorra are the successors to premodern monarchies. Liechtenstein, the Netherlands, Belgium, and Luxembourg were established or gained independence through various methods during the Napoleonic Wars. The State of the Vatican City was recognized as a sovereign state administered by the Holy See in 1929.
Ten of these monarchies are hereditary, and two are elective: Vatican City (the pope, elected at the papal conclave), and Andorra (technically a semi-elective diarchy, the joint heads of state being the elected president of France and the Bishop of Urgell, appointed by the pope).
Most of the monarchies in Europe are constitutional monarchies, which means that the monarch does not influence the politics of the state: either the monarch is legally prohibited from doing so, or the monarch does not utilize the political powers vested in the office by convention. The exceptions are Liechtenstein and Monaco, which are usually considered semi-constitutional monarchies due to the large influence the princes still have on politics, and Vatican City, which is an absolute monarchy. There is currently no major campaign to abolish the monarchy (see monarchism and republicanism) in any of the twelve states, although there is at least a small minority of republicans in many of them (e.g. the political organisation Republic in the United Kingdom). Currently six of the twelve monarchies are members of the European Union: Belgium, Denmark, Luxembourg, the Netherlands, Spain and Sweden.
At the start of the 20th century, France, Switzerland and San Marino were the only European nations to have a republican form of government. The ascent of republicanism to the political mainstream started only at the beginning of the 20th century, facilitated by the toppling of various European monarchies after the end of World War I; as at the beginning of the 21st century, most of the states in Europe are republics with either a directly or indirectly elected head of state.