| Country | Sovereign | Born | Acceded |
| Swaziland | King Sobhuza II | 22 July | 1899 | 10 December | 1899 |
| Japan | Emperor Hirohito | 29 April | 1901 | 25 December | 1926 |
|
Liechtenstein | Prince Franz Joseph II | 16 August | 1906 | 25 July | 1938 |
| Iran | Shah Mohammed Reza Pahlavi | 26 October | 1919 | 16 September | 1941 |
| Thailand | King Bhumibol Adulyadej | 5 December | 1927 | 9 June | 1946 |
| Netherlands | Queen Juliana | 30 April | 1909 | 4 Septemeber | 1948 |
| Monaco | Prince Rainier III | 31 May | 1923 | 9 May | 1949 |
| Belgium | King Baudouin I | 7 September | 1930 | 16 July | 1951 |
| United Kingdom | Queen Elizabeth II | 21 April | 1926 | 6 February | 1952 |
| Jordan | King Hussein | 14 November | 1935 | 11 August | 1952 |
| Norway | King Olav V | 2 July | 1903 | 21 September | 1957 |
| Lesotho | King Moshoeshoe II | 2 May | 1938 | | 1960 |
| Morocco | King Hassan II | 9 July | 1929 | 3 March | 1961 |
| Bahrain | Emir Isa ibn Salman Al Khalifa | 3 June | 1933 | 2 November | 1961 |
| Samoa | Malietoa Tanumafili II | 4 January | 1913 | 15 April | 1962 |
| Vatican City | Pope Paul VI | 26 September | 1897 | 21 June | 1963 |
| Luxembourg | Grand Duke Jean | 5 January | 1921 | 12 November | 1964 |
| Tonga | King Tāufaʻāhau Tupou IV | 4 July | 1918 | 16 December | 1965 |
| Oman | Sultan Qabus bin Said | 18 November | 1942 | 23 July | 1970 |
| United Arab Emirates | President Sheikh Zayed bin Sultan Al Nahyan | | 1918 | 2 December | 1971 |
| Denmark | Queen Margrethe II | 16 April | 1940 | 14 January | 1972 |
| Nepal | King Birendra | 28 December | 1945 | 31 January | 1972 |
| Qatar | Emir Khalifa bin Hamad al-Thani | | 1932 | 22 February | 1972 |
| Bhutan | King Jigme Singye Wangchuk | 11 November | 1955 | 21 July | 1972 |
| Sweden | King Carl XVI Gustaf | 30 April | 1946 | 15 September | 1973 |
| Saudi Arabia | King Khalid | | 1913 | 25 March | 1975 |
| Malaysia | Paramount Ruler Sultan Yahya Petra | 10 December | 1917 | 21 September | 1975 |
| Spain | King Juan Carlos I | 5 January | 1938 | 22 November | 1975 |
| Central African Empire | Emperor Bokassa I | 22 February | 1921 | 4 December | 1976 |
| Kuwait | Emir Jaber Al-Ahmad Al-Jaber Al-Sabah | 29 June | 1926 | 31 December | 1977 |