||King of the Albanians
||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.
|Kingdom of Belgium
||King of the Belgians
||Used since the constitutional oath of Leopold I in 1831. The Belgian popular monarchy is the sole currently in use. The holders of the title have been Leopold I, Leopold II, Albert I, Leopold III, Baudouin, Albert II, and currently Philippe.
|Kingdom of Bulgaria
||King of the Bulgarians
||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.
|Kingdom of the Burgundians
||Kings of the Burgundians
||The title was used from Gjúki to Godomar.
|Kingdom of Croatia
||King of the Croats
||Kralj Hrvata in Croatian, Rex Chroatorum in Medieval Latin, which was later extended to King of the Croats and the Dalmatians (Kralj Hrvata i Dalmatinaca or Rex Chroatorum Dalmatarumque).
|Kingdom of England
||King of the Anglo-Saxons or King of the English
||Rex Anglorum Saxonum or Rex Anglorum in Medieval Latin. Used by the Anglo-Saxon kings of England. The title King of the Anglo-Saxons was first adopted by Alfred the Great when the people of Mercia accepted him as their ruler in the late 9th century. The first king to style himself King of the English was Æthelstan when he conquered the Norse Kingdom of York in 927, making him the first ruler of a united England.
|Frankish Empire / Kingdom of France
||King of the Franks
||Used by the Carolingians from Pepin the Short and in medieval France.
|Kingdom of France
||King of the French
||Used by Louis XVI from 1791 to 1792, and by Louis Philippe I from 1830 until 1848.
||Emperor of the French
||Used by Napoleon I, Napoleon II (however briefly and ceremonially), and Napoleon III during their various reigns.
||Used from 1871 until 1918. The holders of the title were Wilhelm I, Friedrich III, and Wilhelm II.
|Holy Roman Empire
||King of the Romans
||Title of the elected Emperor-to-be.
|Kingdom of Götaland
||King of the Geats
||Götar konung in Swedish, Rex Getarum/Gothorum in Medieval Latin. Title attributed to legendary and historical kings of the North Germanic Geats.
|Kingdom of Greece
||King of the Hellenes
||Used from 1863 to the monarchy's abolition in 1973 (the King had been in exile since 1967). The holders of the title were George I, Constantine I, Alexander, George II, Paul, and finally Constantine II.
||Khagan of the Khazars
|Kingdom of the Lombards
||King of the Lombards
||Rex Langobardorum in Medieval Latin.
|Kingdom of Portugal
||King of the Portuguese
||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).
|Kingdom of the Ostrogoths
||King of the Ostrogoths
|Kingdom of Romania
||King of the Romanians
||Used from 1881 until 1947. The holders of the title were Carol I, Ferdinand I, Carol II and Michael I.
|Kingdom of the Rugii
||King of the Rugii
|Kingdom of Scotland
||King of Scots
||This usage became less common with William III and Mary II, who chose to be called King and Queen of Scotland. The Acts of Union 1707 abolished the Scottish and English thrones and created the Kingdom of Great Britain.
||Emperor of the Serbs and Greeks
||Used between 1346 and 1371. цар Срба и Грка/car Srba i Grka in Serbian. This title was soon enlarged into "Emperor and Autocrat of the Serbs and Greeks, the Bulgarians and Albanians".
|Kingdom of the Suebi
||King of the Suevi in Galicia
|Kingdom of Yugoslavia
||King of Serbs, Croats and Slovenes
||Used from 1918 to 1929, when the title was changed to King of Yugoslavia. The holders of the title were Peter I and Alexander I.
|Kingdom of the Vandals and Alans
||King of the Vandals
|Kingdom of the Visigoths
||King of the Visigoths
|Principality of Wales
||Prince of the Welsh
||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.