| Country | Sovereign | Born | Acceded | ||
| Sikkim | Chogyal Tashi Namgyal | 26 October | 1893 | December | 1914 |
| Luxembourg | Grand Duchess Charlotte | 23 January | 1896 | 14 January | 1919 |
| Japan | Emperor Hirohito | 29 April | 1901 | 25 December | 1926 |
| Ethiopia | Emperor Haile Selassie I | 23 July | 1892 | 2 November | 1916 (Regent) 1930 (Emperor) |
| Muscat & Oman | Sultan Said bin Taimur | 13 August | 1910 | 10 February | 1932 |
| Afghanistan | King Mohammed Zahir Shah | 15 October | 1914 | 8 November | 1933 |
| Liechtenstein | Prince Franz Joseph II | 16 August | 1906 | 25 July | 1938 |
| Iran | Shah Mohammad Reza Pahlavi | 26 October | 1919 | 26 September | 1941 |
| Thailand | King Bhumibol Adulyadej | 5 December | 1927 | 9 June | 1946 |
| Greece | King Paul I | 14 December | 1901 | 1 April | 1947 |
| Denmark | King Frederik IX | 11 March | 1899 | 20 April | 1947 |
| Yemen | King Ahmad bin Yahya | 1891 | 17 February | 1948 | |
| Netherlands | Queen Juliana | 30 April | 1909 | 6 September | 1948 |
| Monaco | Prince Rainier III | 31 May | 1923 | 9 May | 1949 |
| Sweden | King Gustaf VI Adolf | 11 November | 1882 | 29 October | 1950 |
| Belgium | King Baudouin I | 7 September | 1930 | 16 July | 1951 |
| Libya | King Idris I | 12 March | 1889 | 24 December | 1951 |
| United Kingdom Canada Australia New Zealand South Africa Ceylon | Queen Elizabeth II | 21 April | 1926 | 6 February | 1952 |
| Jordan | King Hussein | 14 November | 1935 | 11 August | 1952 |
| Bhutan | King Jigme Dorji Wangchuk | 2 May | 1928 | 27 October | 1952 |
| Saudi Arabia | King Saud | 12 January | 1902 | 9 November | 1953 |
| Nepal | King Mahendra | 11 June | 1920 | 13 March | 1955 |
| Morocco | King Mohammed V | 10 August | 1909 | 1927-53; 1955-57 (Sultan) 1957 (King) | |
| Norway | King Olav V | 2 July | 1903 | 21 September | 1957 |
| Vatican City | Pope John XXIII | 25 November | 1881 | 28 October | 1958 |
| Laos | King Savang Vatthana | 13 November | 1907 | 29 October | 1959 |
| Cambodia | Prince Norodom Sihanouk | 31 October | 1922 | 3 April | 1960 |
| Malaysia | Paramount Ruler Raja Putra of Perlis | 25 November | 1920 | 21 September | 1960 |