(Reuters) - As darkness descended over Damascus on Saturday, July 14, few of its 1.7 million residents could have had any inkling that an all-out battle to wrest the city from the grasp of President Bashar al-Assad was about to begin.
Insurgents gave the operation a name that reflected their hopes of a successful surprise attack on a city long regarded as an impregnable fortress for the Assad family: "Damascus Volcano and Syrian Earthquake".
"There is no going back," Colonel Qassem Saadeddine, a spokesman for the joint command of the Free Syrian Army (FSA), told Reuters after the fighting had broken out. "We have started the operation to liberate Damascus."
The operation, still under way, has come closer to toppling Assad than anything else in the 16-month-old uprising against his rule.
By Sunday, a week after it began, his forces were pushing back, focusing their firepower on rebels in Damascus, Aleppo and the third strategic city of Deir al-Zor in the east and retaking one of five international border posts the fighters had seized.
The concerted attack on the power base of a man whose father was known as "The Lion of Damascus" had been long in the planning, Saadeddine said. It involved 2,500 fighters who had infiltrated the ancient city's suburbs a week earlier, he said.
Insurgents were specially redeployed from other parts of the country for the task, another FSA officer said separately.
The rebels struck first in the city's southern Hajar al-Aswad district, engaging in sustained battles with government troops who must have wondered what had hit them.
The following day, July 15, the scale of the rebels' ambition became clear. That day, a Sunday, a powerful blast tore through a bus in Damascus carrying security forces personnel, wounding many, and fighting spread to three other city districts.
Residents sympathetic to the insurgents burned tires to distract government troops, and government armored vehicles poured into southern Damascus amid reports that the road to the airport had been closed.
Residents of one of the world's oldest continuously inhabited cities described the fighting as the fiercest to touch the capital since the uprising began in provincial towns in March last year.
Assad had - until then - largely succeeded in shielding his capital and its residents from the extreme violence that has convulsed the rest of the country while he has battled to maintain his family's 42-year grip on power.
Even as his tanks and artillery laid waste to parts of other cities, traffic in Damascus circulated, shops and markets kept open, and students continued to study.
But as black smoke rose above Damascus last Sunday and the clatter of machinegun fire rang out - interspersed with the sound of explosions - that illusion of normality was shattered.
On day two of the operation, residents of the central district of Midan said their area had become a war zone with snipers deployed on rooftops and heavy fighting between rebels and government troops.
The supply of electricity and water to some districts was cut. Serious clashes broke out in the districts of Zahera and Tadamon. As violence escalated, activists said tanks were in action on the city's streets, a move analysts interpreted as a sign the government was beginning to panic.
Using classic guerrilla warfare tactics, insurgents sheltered in the city's narrow alleys in the knowledge that armored vehicles and tanks would be unable to follow.
Syrian state TV made little reference to what was unfolding, saying only that security forces were chasing "terrorist groups" that had fled to parts of Damascus.
Video footage uploaded by opposition activists showed men in jeans crouching in sandbagged Damascus alleyways, firing rocket-propelled grenades and machineguns. At that point, on Monday, the rebels said they were surrounded by government troops.
The rebels say they have adapted their tactics, becoming more organized and mobile, operating in smaller groups so as to present a smaller target for government forces. They have also turned increasingly to using homemade bombs or improvised explosive devices (IEDs), they have said.
Though foreign backers keep them supplied with a steady stream of small arms smuggled into Syria, it remains unclear how much direction or support the rebels are receiving, if any, from foreign intelligence services.
On the third day of the offensive, July 17, helicopter gunships were reported to have been pressed into action and the rebels said they had shot down one army helicopter.
Clashes of such intensity so close to Assad's seat of power showed his grip on power was weakening, anti-government activists said.
"When you turn your guns against the heart of Damascus, on Midan, you have lost the city," said Imad Moaz, a Damascus-based activist. Video footage showed the charred facades of shops and buildings.
Israeli military intelligence said Assad hurriedly redeployed troops serving near the Israeli border to Damascus in order to bolster his firepower.
The fourth day of the battle is one that may later be shown to have changed the course of the war. Battles flared in the morning within sight of Assad's presidential palace, an imposing structure that sits on a sandstone hill overlooking the city.
Assad's most trusted lieutenants, led by his brother-in-law Assef Shawkat, were holding a crisis meeting inside a security headquarters when a bomb blast tore through the room. Shawkat was killed, as was the defense minister and another top general.
The intelligence chief would die of his wounds two days later, and the interior minister was also hurt.
Jubilant, the rebels claimed responsibility, boasting that they had pulled off what they called "a turning point in Syria's history", hailing the attack as "the beginning of the end".
It was unclear whether the bomb was delivered by a suicide bomber or whether it had been remotely detonated in the same way that Claus von Stauffenberg had tried and failed to kill Adolf Hitler in 1944.
But the attack - taking out the top layer of Assad's military planners right in the heart of Damascus - gave a huge boost to the rebels while delivering a psychologically devastating blow to the government.
Shell-shocked or lost for words, Assad did not appear on state TV until the following day. He has yet to make any pronouncement on the attack, leaving it to his former army chief-of-staff to vow swift retaliation.
His unproven whereabouts became the subject of rumor, with rebels saying he had left the capital for the coast.
One Western diplomat says it is understood that after the attack the Syrian president called the head of a U.N. peace monitor team, General Robert Mood, promising to implement a U.N. peace plan if the West could get rebels to stop their attacks. Mood and U.N. envoy Kofi Annan were not available to comment.
The authorities promised the rebels they would strike back hard, saying they would "cut off every hand that harms the security of the homeland".
Syrian troops began turning their anti-aircraft guns on rebels in residential areas, pointing the barrels at buildings instead of skywards. Helicopters and artillery fired on Damascus throughout the day.
Blasts also rocked an area close to the base of a feared military unit led by Assad's brother, Maher, while a police station in the Hajar al-Aswad district went up in flames.
Syrian Information Minister Omran Zoabi called the battle for Damascus "the decisive battle in all of Syria" - a comment echoed by Sergei Lavrov, the foreign minister of Russia, Assad's main protector on the world stage.
For the first time, state TV showed government troops exchanging fire with rebels in central Damascus.
"This is the volcano we talked about, we have just started," said Saadeddine, the FSA spokesman.
On day five, helicopter gunships pounded rebel positions. Artillery batteries nestled in the mountains overlooking Damascus rained down shells on two city districts.
Rebels torched and looted the Damascus Province Police headquarters, a huge building, and residents spoke of corpses in the streets.
Scared to venture out, many residents said they had locked themselves inside their own homes for their own safety, while most shopkeepers shuttered their businesses.
Ordinary citizens appeared to have deserted the city's once bustling streets. "Everyone in the neighborhood is arming themselves," said one resident near the Midan district.
"Some with machineguns, some with shotguns. Some even just with knives," the resident added. Fighting flared near the Syrian government's headquarters - a vast Soviet-style building, as well as near the prime minister's office.
Far from Damascus, rebels seized border checkpoints with Turkey and Iraq, the first time they had held control of Syrian frontiers.
On Friday, the sixth day of the rebels' attempt to "liberate" Damascus and the first day of the Islamic holy month of Ramadan, the insurgents suffered a setback.
Under heavy bombardment, they were forced to withdraw from the central district of Midan.
"It is a tactical withdrawal. We are still in Damascus," Abu Omar, a rebel commander, said by telephone.
Elsewhere in the city, rebels set fire to a military barracks after a two-day siege. Opposition sources said the building had been used as a training ground for feared shabbiha militiamen loyal to Assad.
On Saturday, the counter-offensive gathered pace. Syrian troops and armored vehicles pushed into a rebel-held district of Aleppo, the country's biggest city, and struck back in Damascus.
The next day, after an early morning helicopter bombardment, they pushed rebels from the Mezzeh diplomatic quarter of the capital and residents said troops and militia poured in, setting fire to houses and rounding people up.
Many residents had already fled, with tens of thousands of people reported to be entering neighboring Lebanon.
At the hilly Masnaa border crossing on the Lebanese side, Damascenes, many of them wealthy families driving their own air-conditioned cars, could be spotted making their way past border control.
On the border with Iraq, Syrian forces regained control of one of two crossings seized by rebels, Iraqi border guards said, while rebels in Turkey said they had seized a third post there.
"Seizing the border crossings does not have a strategic importance but it has a psychological impact because it demoralizes Assad's force," a senior Syrian army defector in Turkey, Staff Brigadier Faiz Amr, told Reuters by phone.
"It's a show of progress for the revolutionaries, despite the superior firepower of Assad's troops."
The opposition estimates 50,000 out of 280,000 troops have now defected, but the FSA may need more defections to gain the expertise and weaponry required to achieve final victory.
President Barack Obama's administration has been drawing up contingency plans for if and when Assad falls. The New York Times said Washington was talking to Israel about the possibility of securing Assad's chemical weapons - one of the largest stockpiles of its kind in the world.
The Syrian Observatory for Human Rights said 1,261 people had been killed across Syria since last Sunday when the fighting escalated in Damascus, including 299 of Assad's troops, making it by far the bloodiest week in the uprising.
Like a wounded lion, Assad is starting to mount a robust response to the rebels' most audacious attack on his powerbase.
(Reporting by Samia Nakhoul, Dominic Evans, Oliver Holmes, Erika Solomon and Mariam Karouny in Beirut, Suleiman Al-Khalidi in Cilvegozu, Turkey, Saad Shalash near Qaim, Iraq, Khaled Yacoub Oweis in Amman, Steve Gutterman in Moscow and Stephanie Nebehay in Geneva; Editing by Peter Graff and Philippa Fletcher)