Although it is relatively small, with a population of about 150,000, military units loyal to Gaddafi are posted in the city and there is an air force base outside it. It was from Sirte that regime forces fired Scud missiles.
Since the revolution began, Sirte has been a holy grail for the rebels. One of their main grievances has been the unfair distribution of oil wealth throughout the country and Sirte's favourite son has rewarded his hometown handsomely.
On the banks of the Mediterranean, Sirte boasts a university, modern architecture, a conference centre and even a water park. Gaddafi has lavished attention on the two dominant tribes there, buying their loyalty.
Fighters from the east never really got close to the city - a brief advance on Sirte at the end of March was swiftly quashed and regime troops pushed the rebels back towards their stronghold in Benghazi. But this week there were reports the rebels were making advances along the coast.
The Associated Press reported that many Sirte residents were unaware of the assault on Tripoli with communications and power cuts.
"There is no power in Sirte - we are getting in touch with the people inside only through satellite phones," said Hassan al-Daroui, an opposition official. "We are worried that Gaddafi wants to just kill as many people as he can before his demise. He knows he is finished - now he wants to bring Sirte down with him."
There are other cities still under Gaddafi's control, notably Al Khums just east of Tripoli, the southern city of Sebha and a number of tribal towns in the desert.
But the symbolism of Sirte makes it a potent prize for the rebels and residents will be hoping for forgiveness when the rebels come calling.
- Independent