A ballet dancer, an emperor, 'Prince Charming', and a god
Bhutan's fourth king is Jigme Khesar Namgyle Wangchuck. He is 31. When he was crowned king on November 6, 2008, he was the youngest ruling monarch in the world. The Wangchuk dynasty has ruled Bhutan since 1907. His official title is the Dragon King of Bhutan.
His father, the former Dragon King, Jigme Singye Wangchuck, abdicated, or resigned, in 2006 and transferred power to his eldest son.
King Jigme's mother, Queen (Ashi) Tshering Yangdon, was his father's third wife. He has a younger sister and brother.
King Jigme graduated from Oxford University, where he studied political science. His studies have served him well as a king. As soon as he was named king, he introduced democracy to his isolated kingdom. He only took the crown when parliamentary elections had been held.
His father, who ascended to the throne at 16, had laid a lot of the groundwork for him and changed the country into a constitutional monarchy. His father, who was well loved by his people, also introduced the idea of 'Gross National Happiness' in Bhutan. He spread the idea that spiritual and mental health are more important than money.
King Jigme is also celebrated for being handsome. In 2006 he went to Thailand for the 60th anniversary of King Bhumibol Adulyadej's accession to the throne. The Thai media called him Prince Charming and he had legions of infatuated Thai fans.
Cambodia's king, Norodom Sihamoni, is a constitutional monarch. He's just gone to Beijing for a medical check-up. He is the eldest son of Norodom Sihanouk who abdicated in 2004.
King Sihamoni's full title is Preah Karuna Preah Bat Samdech Preah B?romneath Norodom Sihamoni Nai Preah Reacheanachakr Kampuchea. It roughly translates to: His Majesty, King Norodom Sihamoni of the Kingdom of Cambodia.
His younger brother, Samdech Norodom Narindrapong, died in 2003. He also has 14 half-brothers and half-sisters. His mother, Queen Monineath, is his father's seventh wife.
He likes classical dance and music. He is fluent in French and Czech and also speaks good English and Russian. He spent his childhood in Prague. He studied filmmaking in North Korea. On his return home in 1977, he was placed under house arrest by the Khmer Rouge. The Vietnamese invasion of Cambodia secured his release. Soon he moved to Paris to teach ballet.
Emperor Akihito has been on the Chrysanthemum Throne since 1989. His wife is Empress Michiko Sh?da. They have three children.
In Japan, the Emperor - or Tenno in Japanese, which means 'heavenly sovereign' - is the head of the Japanese Imperial Family. He is also the highest authority of the indigenous Shinto religion. The emperor is never referred to by his given name, but only as 'His Imperial Majesty the Emperor' - or 'His Imperial Majesty' - for short.
From the Meiji Restoration in 1868 till the Japanese surrender at the end of the second world war, the Japanese emperor was regarded as an all-powerful god with direct political power. Nowadays, he is a ceremonial figurehead rather than an actual ruler. The country's constitution bars him from being involved in politics. Emperor Akihito's duties consist of greeting foreign heads of state and royals, and performing his duties as a Shinto priest.
The emperor has a keen interest in marine biology, especially in the study of fish species. He lives largely in isolation from public view, yet recently he made a historic appearance on television urging his people not to give up hope and to help each other, following the March 11 tsunami.
King Bhumibol Adulyadej (Rama IX), now 83, has been on the throne since 1946. He is the world's longest-reigning monarch.
Although he is portrayed in Thailand as universally beloved, the king and members of the royal family are protected by a very strict l?se-majest? law. Anyone who voices the slightest criticism of the royals risks being sentenced to decades in prison.
The House of Charki, of which Bhumibol is the ninth king, has been in power since 1782. He was born in Massachusetts in the US and grew up in Switzerland. He ascended the throne at age 18 after his older brother, King Ananda Mahidol (Rama VIII), died from a gunshot wound to the head in his palace bedroom. To this day, it has remained taboo to speculate what happened. Three servants were later executed for Ananda's murder, but foreign historians believe they were innocent.
King Bhumibol is a painter, musician, photographer, author and accomplished sailor. He is treated as a divine figure who can do no wrong. His long reign has seen more than 15 coups and 16 constitutions. According to Forbes magazine, he is the world's richest royal, with a fortune of US$30 billion.