Records of heads of state

Alabaster statue of Pepi II Neferkare (right)

The longest-reigning male monarch (and overall monarch) ever known is disputed between the following candidates:

• Minhti, who ruled the Kingdom of Arakan as an absolute monarch under the title of King of Arakan. He is believed to have ruled for 95 years; however, little documentary evidence exists for this claim.
• Pepi II Neferkare, who ruled the Kingdom of Egypt as an absolute monarch under the title of Pharaoh of Egypt. He is believed to have ruled for either 94 or 64 years.
• Taejo of Goguryeo, who ruled Goguryeo as an absolute monarch under the title of Taewang ("The Greatest of all Kings"). He is believed to have ruled for either 93 years or 68 years.

The longest undisputed reigning male monarch (or monarch regardless of sex) known is Sobhuza II, who ruled the Kingdom of Swaziland (after 1973 as an absolute monarch) under the title of Paramount Chief of Swaziland and later King of Swaziland. He ruled for 82 years, 8 months, 11 days.

The longest current reigning male monarch is Hassanal Bolkiah, who is the Sultan and Yang di-Pertuan of Brunei ("(he) who is Lord"), an absolute monarch of Brunei Darussalam.

The longest current reigning constitutional male monarch is Carl XVI Gustaf, who is the King of Sweden.

The longest reigning female monarch ever is Elizabeth II, who is currently the Queen of the United Kingdom and other Commonwealth realms, and is a constitutional monarch. She has been Queen of the United Kingdom, Australia, Canada, and New Zealand, since 6 February 1952, but all of the other countries she is at present queen were not independent at the time of her accession.

The longest current reigning female monarch is Elizabeth II, who is the Queen of the United Kingdom and other Commonwealth realms, and is a constitutional monarch. She has been Queen of the United Kingdom, Australia, Canada and New Zealand, since February 6, 1952, but all of the other countries she is at present queen of had yet to gain independence at the time of her accession.

Fidel Castro

The longest-serving non-royal head of state in the 20th and 21st centuries was Fidel Castro, who held the titles of Prime Minister of Cuba, First Secretary of the Integrated Revolutionary Organizations, First Secretary of the Central Committee of the United Party for the Socialist Revolution of Cuba, First Secretary of the Central Committee of the Communist Party of Cuba, President of the Council of State, and President of the Council of Ministers of the Republic of Cuba. He served overall for 52 years, 2 months, and 3 days but was only head of state per se from 1976 to 2008 (31 years, 2 months and 22 days).

Teodoro Obiang Nguema Mbasogo

The longest-serving and longest current serving male president ever is Teodoro Obiang Nguema Mbasogo, who is currently the President of the Republic of Equatorial Guinea, who seized power in a coup in 1979.

Vigdís Finnbogadóttir

The longest serving female non-royal head of state and longest serving female president ever was Vigdís Finnbogadóttir, who was the President of the Republic of Iceland. She served for 16 years.

Officially, the current Emperor of Japan, Naruhito is the 126th in line from the first emperor, Jimmu, who is variously believed to have reigned in the 1st or 7th century BC. The earliest documentary 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.

Queen Elizabeth II of the United Kingdom is well-documented as being descended from Arnulf of Metz (c. AD 582–640), forefather of Charlemagne, thus representing a lineage of 47 generations. (See Descent of Elizabeth II from the Franks.)

The Ottoman Empire lasted for 36 sultans in 21 generations, from Osman I to Mehmed VI for 623 years. (See List of sultans of the Ottoman Empire.)

The heaviest monarch is believed to have been Taufa'ahau 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.[2]

Maharana Pratap was the tallest head of state. He was the King of Mewar. His remains were measured to indicate a height of at least 7 ft 5 in (226 cm).[3]

President Benito Juárez of Mexico was reportedly the shortest world leader, standing at 4 ft 6 in (1.37 m).

According to legends, the youngest ruler is Shapur II who was crowned in utero when a crown was placed on the belly of Hormizd II's wife after Hormizd II died. However, according to Shapur Shahbazi, it is unlikely. Other claims as the youngest ruler include John I of France and Alfonso XIII of Spain who were both crowned on the day of their birth.