“If the Allies at the peace table at Versailles had allowed a Hohenzollern, a Wittelsbach and a Habsburg to return to their thrones, there would have been no Hitler. A democratic basis of society might have been preserved by a crowned Weimar in contact with the victorious Allies.”

Monarchy has been one of the predominant forms of government throughout recorded history, but individual monarchies have never been permanent.

Dynasties have ended through conquest, revolution, constitutional change, war, national unification, partition and popular decision. Some monarchies have disappeared with the states over which they ruled; others have later been restored.

The history of former monarchies therefore deserves more careful treatment than the assumption that monarchy simply belongs to an earlier stage of political development.

For many centuries the Holy Roman Empire formed one of the principal political frameworks of Central Europe.

Its medieval roots were associated with the revival of imperial authority in western Europe. 

Charlemagne was crowned Emperor by Pope Leo III in Rome in 800, while the polity conventionally known to historians as the Holy Roman Empire is commonly traced from the coronation of Otto I as Emperor in 962.

The Empire was never a single centralised nation-state. It contained kingdoms, principalities, duchies, bishoprics, free cities and numerous other territories whose rulers possessed varying degrees of autonomy.

The imperial office was elective rather than straightforwardly hereditary. A small group of Prince-Electors acquired the recognised right to choose the Emperor, a system formally codified in the Golden Bull of 1356.

Religious division following the Reformation and the political consequences of the Thirty Years' War altered the Empire profoundly. The Peace of Augsburg of 1555 is associated with the principle cuius regio, eius religio — broadly, that the religion of a territory would follow that of its ruler — although the later constitutional settlement was considerably more complicated.

The Holy Roman Empire was finally dissolved in 1806 during the Napoleonic Wars.

Hanover provides an interesting British connection. George I was Elector of Hanover when he succeeded to the British throne in 1714. Hanover became a kingdom in 1814, during the reign of George III, and remained in personal union with the British Crown until the death of William IV in 1837. Because Hanoverian succession law did not permit Victoria to succeed while an eligible male heir remained, the Hanoverian Crown passed instead to her uncle Ernest Augustus.

The First World War transformed the political map of Europe.

King George V of the United Kingdom, Kaiser Wilhelm II of Germany and Emperor Nicholas II of Russia were closely related through Europe's interconnected royal houses. Such family relationships, however, were not sufficient to prevent conflict between their states.

The Russian monarchy ended amid revolution in 1917. At the end of the war the German and Austro-Hungarian monarchies also collapsed, while political upheaval reshaped much of Central and Eastern Europe.

Archduke Franz Ferdinand, whose assassination at Sarajevo in 1914 precipitated the immediate crisis which led to the First World War, was the nephew and heir presumptive of Emperor Franz Joseph I. Franz Joseph's only son, Crown Prince Rudolf, had died in 1889.

The disappearance of these monarchies arose from war, military defeat, nationalism, revolution and profound social and political change rather than from any single cause.

Spain provides an important example of a monarchy restored in the twentieth century.

The reign of Alfonso XIII ended in 1931, when he left Spain following municipal elections and the Second Spanish Republic was proclaimed.

The Spanish Civil War followed from 1936 to 1939, after which General Francisco Franco governed as dictator.

In 1947 Spain was legally constituted as a kingdom, although Franco remained Head of State. Prince Juan Carlos was designated as his successor in 1969.

Following Franco's death in 1975, Juan Carlos I became King. He subsequently played an important role in Spain's transition to parliamentary democracy.

The Constitution of 1978 established Spain as a parliamentary monarchy. Sovereignty resides in the Spanish people, while the King is Head of State and symbol of the unity and permanence of the State.

Spain therefore demonstrates that restoration need not mean a return to the constitutional arrangements of an earlier age. A restored monarchy may itself become part of a new democratic settlement.

Portugal possessed one of Europe's oldest monarchies.

King Carlos I and his elder son Luís Filipe were assassinated in Lisbon in 1908. Carlos's younger son succeeded as Manuel II.

Political instability continued and the revolution of October 1910 brought the monarchy to an end. Manuel II spent the remainder of his life largely in exile in England and died without children in 1932.

Portuguese monarchism nevertheless continued, and members of the House of Braganza remain prominent in cultural, charitable and historical life.

Modern Greece became an independent monarchy in the nineteenth century after the struggle for independence from Ottoman rule.

Its first monarch, Otto of Bavaria, was deposed in 1862 and was succeeded by George I, originally a Danish prince.

The twentieth-century history of the Greek Crown was turbulent. The monarchy was abolished in 1924 and restored following a plebiscite in 1935.

King Constantine II succeeded in 1964. Following the military coup of 1967 and his unsuccessful attempt at a counter-coup later that year, he left Greece.

The military regime abolished the monarchy in 1973. After the restoration of democratic government, a new referendum was held on 8 December 1974, and voters chose by a substantial majority to retain the republic.

Constantine accepted the result and died in Athens in 2023.

Modern Bulgaria emerged from Ottoman rule as an autonomous principality in 1878.

Full independence was proclaimed in 1908, when Ferdinand assumed the title of Tsar.

The monarchy ended following the Second World War. The young Simeon II was deposed after the 1946 referendum and went into exile.

His later career was remarkable. Returning to Bulgaria after the fall of communism, Simeon Saxe-Coburg-Gotha entered democratic politics and served as Prime Minister of the Republic of Bulgaria from 2001 to 2005.

The disappearance of a monarchy does not necessarily mean the disappearance of its royal house.

Members of former reigning dynasties remain active in cultural, charitable, academic and public life throughout Europe and elsewhere. Some advocate restoration; others do not. Many preserve archives, historic properties, family traditions and cultural connections with the countries their ancestors once ruled.

Their constitutional position should nevertheless be described accurately. A person may be head of a former royal house or claimant to a historical throne without being a reigning Sovereign or possessing legal public authority.

History shows that restoration is possible, but never inevitable.

Britain restored its monarchy in 1660. Greece restored its monarchy in 1935 before finally becoming a republic in 1974. Spain restored its Crown in 1975 as part of a transition which culminated in parliamentary democracy.

The Crown Society supports the study and, where appropriate, the peaceful and constitutional restoration of monarchy. Any genuine restoration in the modern world, however, must be rooted in the law, political circumstances and wishes of the people concerned.

Monarchy survives most successfully not by attempting to recreate the past unchanged, but by carrying continuity into new constitutional circumstances.