| Country | Sovereign | Born | Acceded | Consort | Heir |
 Kingdom of Swaziland |  King Sobhuza II | 22 Jul 1899 | 10 Dec 1899 | (70 wives) | |
 State of Japan |  Emperor Hirohito | 29 Apr 1901 | 25 Dec 1926 |  Empress Nagako (1903) |  Crown Prince Akihito (1933) |
 Principality of Liechtenstein |  Prince Franz Joseph II | 16 Aug 1906 | 25 July 1938 |  Princess Georgina (1921) |  Her. Pr. Hans Adam (1945) |
 Imperial State of Iran |  Shah Mohammad Reza Pahlavi | 26 Oct 1919 | 16 Sep 1941 |  Empress Farah (1938) |  Crown Prince Reza (1960) |
 Kingdom of Thailand |  King Bhumibol Adulyadej | 5 Dec 1927 | 9 Jun 1946 |  Queen Sirikit (1932) |  Crown Prince Vajiralongkorn (1952) |
 Kingdom of the Netherlands |  Queen Juliana | 30 Apr 1909 | 4 Sep 1948 |  Prince Bernhard (1911) |  Princess Beatrix (1938) |
 Principality of Monaco |  Prince Rainier III | 31 May 1923 | 9 May 1949 | .jpg/200px-Gracia_van_Monaco_(1972).jpg) Princess Grace (1929) |  Her. Pr. Albert (1958) |
 Kingdom of Belgium |  King Baudouin I | 7 Sep 1930 | 16 Jul 1951 |  Queen Fabiola (1928) |  Prince Albert (1934) |
 United Kingdom of Great Britain & Northern Ireland
Canada |  Queen Elizabeth II | 21 Apr 1926 | 6 Feb 1952 |  Prince Philip, Duke of Edinburgh (1921) |  Prince Charles, Prince of Wales (1948) |
 Hashemite Kingdom of Jordan |  King Hussein | 14 Nov 1935 | 11 Aug 1952 |  Queen Noor (1951) |  Crown Prince Hassan (1947) |
 Kingdom of Norway |  King Olav V | 2 Jul 1903 | 21 Sep 1957 |  Crown Prince Harald (1937) | |
 Kingdom of Lesotho |  King Moshoeshoe II | 2 May 1938 | 12 Mar 1960 | Queen 'Mamohato (1941) | Prince Letsie (1963) |
 Kingdom of Morocco |  King Hassan II | 9 Jul 1929 | 3 Mar 1961 | Princess Lalla Latifa (1946) | Crown Prince Mohammed (1963) |
 Emirate of Bahrain |  Emir Isa ibn Salman Al Khalifa | 3 Jun 1933 | 2 Nov 1961 | Crown Prince Hamad (1950) | |
 Independent State of Western Samoa |  Malietoa Tanumafili II | 4 Jan 1913 | 15 Apr 1962 | Lili Tunu | |
 Vatican City |  Pope Paul VI | 26 Sep 1897 | 21 Jun 1963 | ||
 Grand Duchy of Luxembourg |  Grand Duke Jean | 5 Jan 1921 | 12 Nov 1964 |  Grand Duchess Josephine- Charlotte (1927) | Her. GD. Henri (1955) |
 Kingdom of Tonga |  King Tāufaʻāhau Tupou IV | 4 Jul 1918 | 16 Dec 1965 |  Queen Halaevalu Mataʻaho ʻAhomeʻe (1926) | Crown Prince Siaosi Tupou (1948) |
 Sultanate of Oman |  Sultan Qabus bin Said | 18 Nov 1940 | 23 Jul 1970 | Princess Kamila (1951) | |
 United Arab Emirates |  President Sheikh Zayed bin Sultan Al Nahyan | 6 May 1918 | 2 Dec 1971 | Crown Prince Khalifa (1948) | |
 Kingdom of Denmark |  Queen Margrethe II | 16 Apr 1940 | 14 Jan 1972 |  Prince Henrik (1934) |  Crown Prince Frederik (1968) |
 Kingdom of Nepal |  King Birendra | 29 Dec 1944 | 31 Jan 1972 |  Queen Aishwarya (1949) | Crown Prince Dipendra (1971) |
 State of Qatar |  Emir Khalifa bin Hamad al-Thani | 17 Sep 1930 | 22 Feb 1972 | Crown Prince Hamad (1952) | |
 Kingdom of Bhutan |  King Jigme Singye Wangchuk | 11 Nov 1955 | 21 Jul 1972 | ||
 Kingdom of Sweden |  King Carl XVI Gustaf | 30 Apr 1946 | 15 Sep 1973 |  Queen Silvia (1943) |  Prince Bertil (1912) |
 Kingdom of Saudi Arabia |  King Khalid | 13 Feb 1913 | 25 Mar 1975 |  Crown Prince Fahd (1921) | |
 Federation of Malaysia |  Paramount Ruler Sultan Yahya Petra | 10 Dec 1917 | 21 Sep 1975 | Raja Perempuan Zainab (1917) | |
 Kingdom of Spain |  King Juan Carlos I | 5 Jan 1938 | 22 Nov 1975 |  Queen Sofia (1938) |  Felipe, Prince of Asturias (1968) |
 Central African Empire |  Emperor Bokassa I | 22 Feb 1921 | 4 Dec 1976 |  Empress Catherine |  Crown Prince Jean-Bédel (1973) |
 State of Kuwait |  Emir Jaber Al-Ahmad Al-Jaber Al-Sabah | 29 Jun 1926 | 31 Dec 1977 | Crown Prince Saad (1930) |