Shaikh Jaber has been at the helm during Kuwait's worst modern crises - first, the eight-year Iraq-Iran war which started in 1980, an economic crash in 1982, and then the Iraqi invasion - but even these did not dent his popularity.
He survived an attempt on his life in May 1985 when suspected Shia militants intercepted his motorcade with a car bomb, apparently in protest at Kuwait's support for Iraq in the conflict with Shia-dominated Iran. He escaped with minor bruises.
Shaikh Jaber's darkest hour as amir came on 2 August 1990 when Iraqi troops stormed over the border, beginning a seven-month occupation that annexed the emirate as the 19th province of Iraq.
The oil boom in the late 1970s and early 1980s fuelled massive speculation on the unofficial but tolerated Suq al-Manakh stock market that collapsed in 1982, leaving the economy reeling under tens of billions of dollars of debt.
Since his reign began, the national assembly, the first elected parliament in the Gulf region, was dissolved twice - the first time for six years in 1986 during which articles of the constitution were also suspended, the second time for two months in 1999.
In September 2001, Shaikh Jaber suffered a minor brain haemorrhage and spent four months in Britain undergoing treatment. Since then, his health was on the decline.
Shaikh Sabah al-Ahmad al-Sabah
became prime minister in 2003
After his health deteriorated in recent years, the amir delegated most of his public duties to the prime minister. He spent two and a half months out of the country after undergoing leg surgery in the United States in May 2005.
For the first time since Kuwait gained independence from Britain in 1961, the amir in 2003 split the posts of crown prince and prime minister which were held by the ailing crown prince Shaikh Saad al-Abdullah al-Sabah since early 1978, naming Shaikh Sabah al-Ahmad al-Sabah as prime minister.
Born in 1928, Shaikh Jaber is the third son of the 10th amir of Kuwait, Shaikh Ahmad al-Jaber al-Sabah, who ruled from 1921 to 1950.
Shaikh Jaber became director of public security of the oil-rich al-Ahmadi region in 1949, at the age of 21.
In 1959, he was named president of Kuwait's financial department, a title which changed after Kuwaiti independence in 1961 to minister of finance and oil.
He held the post in addition to running the Ministry of Commerce and Industry for 11 months.
Reserve Fund for Future
Shaikh Jaber was behind the creation of the emirate's Reserve Fund for Future Generations (RFFG), a powerful tool that channelled the state's surplus funds into long-term investments, mostly in Europe and the United States.
The Fund proved its worthiness during the emirate's oil boom in the 1970s. Its assets had reached more than $100 billion by the time deposed Iraqi president Saddam Hussein's troops invaded the emirate in August 1990.
Record global high prices of oil
has boosted Kuwait's economy
Some $70 billion were spent on liberation by a US-led international coalition in 1991 and subsequent reconstruction.
The Fund has since been replenished, topping $100 billion again, and it is expected to swell by an additional $30 billion by the end of the current fiscal year ending 31 March 2006, on the back of record high oil prices.
Shaikh Jaber was named prime minister on the accession to the throne in November 1965 of his cousin Shaikh Sabah al-Salem al-Sabah after the death of Shaikh Abdullah al-Salem al-Sabah, the 11th amir of Kuwait.
The following year, Shaikh Jaber was appointed crown prince and he retained the two positions until his own accession to the throne on 31 December 1977. He was sworn in parliament on 1 January 1978.
He was from the al-Jaber branch of the al-Sabah family, which by tradition alternates the position of head of state with the al-Salem branch, to which Shaikh Saad is affiliated.
Shaikh Jaber, who married several times, has a large number of sons and daughters, but none of them has reached the status of a cabinet minister.
Under the Kuwaiti constitution, the amir is the head of state who is highly respected and his status is protected. He is also supreme commander of the armed forces.