Heads of state throughout the world and at all periods of history may be ranked according to characteristics such as length of time holding that position; age of accession or death; or physical attributes.
However, the longest undisputed reigning ruler of a sovereign state is Louis XIV, who ruled the Kingdom of France for 72 years, 3 months, and 18 days.
[9] The longest reigning female monarch of a completely sovereign state is Elizabeth II, who was the Queen of the United Kingdom and other Commonwealth realms.
[13] The longest-serving male president ever was Malietoa Tanumafili II of Samoa, who held the office of O le Ao o le Malo for a special lifetime term (in derogation from the normal term length of five years), for 45 years and 130 days overall; first alongside Tupua Tamasese Meaʻole from 1962 to 1963 and then as sole head of state from 1963 to 2007.
[16] The longest current serving male president is Teodoro Obiang Nguema Mbasogo of Equatorial Guinea, who seized power in a coup in 1979.
[19] Salome Zourabichvili has served for longer as President of Georgia, as she was elected in 2018, but the office has been disputed between her and Mikheil Kavelashvili since the end of her term in 2024.
The oldest ruler at the time of taking office is Prem Tinsulanonda, who became regent of Thailand at 96 years 97 days old and ruled for several months.
[30] The oldest monarch at the time of accession is Emir Nawaf Al-Ahmad Al-Jaber Al-Sabah of Kuwait, who started his reign at 83 years, 96 days.
The oldest undisputed monarch is Jean, who was Grand Duke of Luxembourg from 1964 until his abdication in 2000; he lived from 5 January 1921 until his death on 23 April 2019 at 98 years, 108 days.
The oldest living female former head of state is Violeta Chamorro, who served as President of Nicaragua and was born on 18 October 1929 and is currently 95 years, 119 days old.
The earliest documented evidence is only for the 29th emperor, Kinmei (AD 509–571); however, this is sufficient such that even the most conservative of estimates still places the Japanese imperial family as among the oldest lines in the world today.
The highest post-nominal number representing a member of a royal house is 75, used by Count Heinrich LXXV Reuss zu Schleiz (r. 1800–1801).
[38] The heaviest monarch is believed to have been Tāufaʻāhau Tupou IV, King of Tonga from 1965 to 2006, who at his peak in 1976 was measured as 208.7 kg (460 lb), though he subsequently lost around 40% of his weight.
[43] Herodotus wrote in Histories (7:117) that "Xerxes was in stature the tallest of all the Persians, falling short by only four fingers of being five royal cubits in height."