His Highness Sheikh Jaber III, Emir of Kuwait, who died yesterday aged 79, fled into exile when Saddam Hussain invaded his oil-rich emirate in 1990.

While the ruler and his entourage lived in comfort in Saudi Arabia, his citizens endured seven months of murder, rape, and torture at the hands of marauding Iraqis. Nevertheless, the Emir returned in March the next year to a tumultuous welcome from his liberated subjects after an American and British-led coalition smashed its way into Kuwait City. Twenty-four British military personnel died in Operation Desert Storm, nine of them victims of "friendly fire" by the Americans.

Sheikh Jaber led his country, which produces 10 per cent of the world's crude oil, from his accession in 1977, as the 13th ruler of a 245-year-old dynasty. Decisive in his early years, Jaber was traumatised by the invasion and rarely appeared in public after his family dynasty was restored.

Unlike the flamboyant race-going princes of the Lower Gulf, Jaber liked to live modestly, and before a failed attempt on his life in the mid-1980s often liked to go shopping incognito in the souk dressed in street clothes.

A victim of ill health since he suffered a stroke in 2001, Jaber nevertheless pushed through democratic reforms in his twilight years, which have seen women take public office and gain the right to vote at the next national assembly elections in 2007.

In recent months, however, constitutional storm clouds have gathered over the Kuwaiti royal family and its ailing leadership. The new ruler, Sheikh Saad al Abdullah al Sabah, a distant cousin who was chosen as heir apparent in 1978, has succeeded Jaber, but is now frail.

The influential head of the National Guard, Sheikh Salem al Ali al Sabah, fourth in line to succeed, openly called in the autumn for a "three-person committee" to assist the leadership in its executive functions.

Such a proposal, while accompanied by a loyalty statement, is unprecedented in a conservative Gulf society such as Kuwait and may presage a bout of infighting within the elite. Sheikh Jaber, a consensus builder by instinct, always strove to avoid such family feuds.

In the past, with rare exceptions, Kuwaitis have never questioned the legitimacy of their leaders, but the mood in the Gulf is changing. In recent months, the ill health of the Emir and the Crown Prince has left decision-making largely in the hands of the appointed prime minister, Sheikh Sabah al-Ahmed al-Sabah, Jaber's younger brother.

Following the liberation in 1991, Kuwait became, with Bahrain, one of America and Britain's staunchest allies. The Emir agreed to American troops using Kuwait as a launch pad for the 2003 invasion of Iraq that overthrew Saddam. At the time, Saudi Arabia would help the Americans only covertly, amid widespread opposition to the war in the "Arab street".

Sheikh Jaber's formative years and early career in public life preceded Kuwait's rise as a global hydrocarbons exporter. Although oil production started in 1946, Kuwait (meaning little fort) was still under British protection. It is to the royal family's credit that Kuwait became the first oil state to work out a comprehensive policy of redistribution of wealth once substantial oil revenues arrived.

Sheikh Jaber al Ahmad al Sabah was born on June 29 1926, the third son of a former Emir, Sheikh Ahmad al Jaber, who ruled until 1921, and his first wife, Shaikha Bazba. Jaber's education took the form traditional for Arab royalty at the time, with tutors at home and Koranic studies.

As an adult, his first job was to head security in the oil fields in 1949, but he became involved in negotiations about increased royalties with foreign oil companies. Later, he became head of the pre-independence government's finance department, which became a ministry when the British handed over full sovereignty in 1962.

Jaber's remarkable domestic achievement was to establish a Fund for Future Generations against the day when the oil revenues run dry. Now estimated to stand at around ￡33 billion, this fund is a repository for 10 per cent of oil revenue.

Jaber became Emir on the death of his cousin in 1977, following a family agreement whereby the succession alternates between two different strands of the royal family.

The succession had been cemented in 1966 when Jaber became Crown Prince, yet his reign was to experience early trauma with the Iranian revolution in 1979 and the outbreak of the Iran-Iraq war a year later. In the latter conflict Kuwait resolutely supported Saddam, which resulted in tensions among the Shia inhabitants of Kuwait who were sympathetic to Iran. Jaber had allowed the suspended national assembly, elected on a male-only franchise, to be reconstituted in 1981, but he was forced to dissolve it five years later as tensions rose, including an attempt on his life when, in 1985, a would-be assassin fired shots at his motorcade.

In 1990, as Saddam made increasingly bombastic threats against Kuwait, demanding a share of its oil wealth, Jaber initially sought to appease the Iraqi dictator. Kuwait had contributed billions of dollars to Saddam's war against Iran and the Emir thought the blackmailer could be bought off, and naively assumed that no Arab nation would ever attack another.

On the morning of August 2 1990 Jaber's worst fears were realised and, in the brief resistance that followed the Iraqi attack, the Emir's younger brother, Sheikh Fahad, was killed by a sniper. As the Emir escaped in a motorcade across the land border with Saudi Arabia, Baghdad claimed it was acting in support of an internal revolution.

The short-lived puppet government under a Kuwaiti quisling lasted only six days. Kuwait became the 19th governorate of Iraq and Saddam nominated his cousin, Ali Hassan Al Majeed, better known as "Chemical Ali" and now on trial in Baghdad, as gauleiter.

It was Jaber's darkest hour, made worse when reports began flowing in of Iraqi looting, pillage, rape and torture of Kuwaiti civilians. The retreating Iraqi forces in 1991 stole hundreds of millions of dollars and torched the oil fields.

Based, during his exile, at the Saudi summer capital of Taif, Jaber directed a highly successful lobbying campaign in western capitals to generate positive spin for the plight of the Kuwaitis. This was all the more remarkable in view of the fact that many pro-Israel politicians in America considered Kuwait's leaders to be "poisonous and anti-Semitic."

Jaber also needed to gain the support of all Kuwaitis. He met opposition leaders while in exile and promised them he would restore the national assembly. He did this in 1992, and in 1999 gave women the right to vote, a pledge that is due to be implemented next year.

Nevertheless, Jaber's reclusive conduct after his restoration can be attributed to his feelings of guilt at the atrocities committed against his citizens. More than 1,000 Kuwaitis are still officially listed as missing.

On a visit to Taif, former prime minister John Major recorded in his memoirs how downbeat and distressed he found the Emir at the rape of his country. His concern then was that Saddam would get away with a partial withdrawal and remain a threat for years to come.

Jaber preferred a simple routine; he would often lunch on a cup of yoghurt and some pitta bread. In exile, he said little and prayed often, leaving much of the diplomatic round to the Crown Prince. He once said that his only aim was to have a "small tent in his country once the Iraqis had gone - not palaces or luxury".

Nevertheless, for all the consensus he built, Jaber was determined to seek revenge, particularly on the community of expatriate Palestinians who had supported the invasion. Some 450,000 of them were expelled from Kuwait after the liberation. The stand-off ended only when the Palestinian leader, Mahmoud Abbas, visited Kuwait in 2004 and apologised for the PLO's previous support for Saddam's claims on Kuwait.

Sheikh Jaber al Ahmad al Sabah had a large extended family. He is on record as having had 13 wives, 21 sons, and 18 daughters, spread over a period of nearly 40 years. He was divorced only from his first wife.

His eldest son is Sheikh Mubarak, who was born in 1945 to Jaber's second wife Sharifa. His youngest son was born in 1984.