As the second son of Prince (later king) Mahendra, the infant Gyanendra was declared king for two months (19501951) when the rest of his family was in exile in India, but was not internationally recognised. His grandfather Tribhuvan was returned to the throne shortly after, when the Rana family conceded power. Fifty years later, when his nephew Dipendra purportedly staged a murder suicide, killing most of the family, including King Birendra (Dipendra's father, and Gyanendra's brother), Gyanendra became king again.

As king he has sought to exercise active control over the government, twice in three years dismissing the Prime Minister to appoint governments of his choosing. His brother Birendra had negotiated a constitutional monarchy in 1990 in which he, as King, played a minor role in government, and Gyanendra's changes to this constitutional settlement have been met with censure from critics of his government. Gyanendra took control once again on February 1, 2005, accusing prime minister Sher Bahadur Deuba's government of failing to make arrangements for parliamentary elections and of being unable to restore peace in the country, which currently suffers from widespread terrorism and insurgency from Maoists.

Began his career as the Chairman of Advisory Committee for the Coronation of His late Majesty King Birendra Bir Bikram Shah in 1975, King Mahendra Trust for Nature Conservation from 1982 to 2001, Lumbini Development Trust from 1986 to1991. He was member of Honour of World Wildlife Fund for Nature, Founding Member: 1001-Nature Trust (1986). Ascended the Throne of the Kingdom of Nepal in 2001. Supreme Commander of the Royal Nepalese Army. He was patron of Royal Nepal Academy of Science of Technology, King Mahendra Trust for Nature Conservation, Lumbini Development Trust, Pashupati Area Development Trust. He is the Chancellor of Tribhuvan University and Mahendra Sanskrit University.

King Gyanendra represented His late Majesty King Birendra Bir Bikram Shah at the ceremony marking the accession of His Majesty King Jigme Singye Wangchuck to the throne of Bhutan in 1972. At the Wedding of The Prince of Wales of the UK in 1981. At the funeral of H.E. Josip Broz Tito, President of Yugoslavia, 1980. Others: Inauguration of the Japan Chapter of the King Mahendra Trust for Nature Conservation in Tokyo, Japan, 1986. Attended the World Wildlife Conference in San Francisco, United States of America, 1976.

He studied in Senior Cambridge from St. Joseph's College of Darjeeling in India in 1966 and graduated from Tribhuvan University, Kathmandu in 1969. King Gyanendra married Her Majesty Queen Komal Rajya Laxmi Devi Shah in 1970). He has one son and one daughter.