BEIRUT (Reuters) - The world saw only a handful of pictures of Assef Shawkat. Few knew what he really did, or what power he wielded.
But any Syrian would have told you that President Bashar al-Assad's 62-year-old brother-in-law, reported to have been killed in a suicide attack in Damascus on Wednesday, was one of the pillars of Assad family rule.
Despite a difficult entry into the Assad clan, Shawkat was widely seen as a member of the president's inner circle. After years as deputy head and then chief of military intelligence, he had become deputy defence minister, another position that allowed him to wield power out of the limelight.
U.S. diplomatic cables published by Wikileaks described him as both a clever, well-read officer and as part of Syria's "killing problem".
Washington imposed sanctions on Shawkat in 2006 on suspicion that he orchestrated the assassination of former Lebanese prime minister Rafik al-Hariri and other officials seen as threats to Syrian influence.
"Shawkat has been a key architect of Syria's domination of Lebanon, as well as a fundamental contributor to Syria's long-standing policy to foment terrorism against Israel," the U.S. Treasury said at the time.
Activists fighting to topple Assad saw Shawkat as the iron fist of the establishment, pushing for a ruthless approach to the rebellion. But Lebanese security sources close to the Assads said Shawkat had always acted as part of a powerful, close-knit inner circle.
"Shawkat prefers force but he is just one part of the decision-making group. This regime is like a network," said a Lebanese security source close to the Damascus centre of power.
The "network" is mostly from Assad's minority Alawite sect, which dominates Syria's elite but is now confronted with an uprising led by the underdog Sunni Muslim majority.
When president Hafez al-Assad died in 2000 after almost 30 years in charge, Shawkat was believed to be one of a handful of people who helped to run the country before Bashar took power.
During Bashar's election campaign, critics made mock posters with caricatures of him, his brother Maher and Shawkat. The caption read: "For the first time in Syria: Vote for one president, get two more absolutely free."
The joke highlighted the shift in Syrian governance after Hafez's death, from a personality cult carefully led by one man to a group of co-captains.
Opposition figures say the lack of transparency in government and the secrecy that shrouds top figures is one reason for their difficulty in trying to negotiate with Syria's rulers.
They say Shawkat appeared in public only twice after the revolt grew into an armed insurgency. He went to Zabadani, a mountain resort near the capital, when the rebels temporarily seized it. Later he went to the city of Homs, centre of the uprising, when the army launched an assault on rebel-held areas.
Hundreds were killed in both places.
"Both times, the same thing happened. He met with some rebels, he told them: 'Move out of the area and we will turn the lights and water back on. The assault will stop'," said one activist, who asked not to be identified.
"Both times, the rebels withdrew from their positions. The lights and water went back on. And both times, the shelling started the next day.
"This is what puzzles us: Did he trick the rebels? Or had he simply lost the authority to tell the army what to do?"
Shawkat's marriage into the Assad family brought him mixed fortunes, and his life read in some ways like something out of the soap operas he was said to write as a hobby.
Shawkat was a member of the Alawite sect, an offshoot of Shi'ite Islam that has dominated the elite since Hafez al-Assad took power in 1970. But other than religion, he had little in common with the Assad children, born into the ruling class.
He left his modest home in the coastal Tartous province and joined the army, working his way up through the ranks.
But his big break came when he divorced his first wife and married Bushra, Bashar's older sister.
The move took nerve and nous, given that both the late president and his eldest son and heir apparent Basil both disapproved of Shawkat, according to diplomats and members of the security services.
Basil considered Shawkat too lowly to join the Assad clan and even jailed him in 1993 to keep him away from Bushra, according to security sources and to U.S. diplomatic cables published by Wikileaks.
Then a year later Basil died in a car crash, and the couple married. Hafez al-Assad made Shawkat deputy chief of military intelligence, and in 2005 Bashar appointed him to head the unit. positions that enabled him to pull strings in Syria's dealings with its troubled neighbours, Iraq and Lebanon.
One leaked American cable called him "the comeback player of the regime".
But Shawkat's relationship with the new generation of Assads appears to have been tempestuous.
Diplomats say Maher, Bashar's younger brother and head of the elite Republican Guard, once shot him. Some believe Bashar himself was wary of his brother-in-law and his sister, who was the favourite of their late father.
"We do know there was a certain amount of rivalry ... Shawkat and Bushra for quite a long time used to think of themselves as more presidential than Bashar and (his wife) Asma," said British historian Patrick Seale.
Whatever the personal tensions, Shawkat never seems to have wavered in his determination to keep the ruling clan and the Alawite establishment in power.
"They know their fate is shared and that could mean paying the ultimate price," said the Lebanese source with close knowledge of the Damascus government.
"If one of them falls, they all do."
Editing by Douglas Hamilton, Samia Nakhoul and Kevin Liffey