roles in the rallies, which at their height drew around 100,000 people, mostly supporters of ousted ex-premier Thaksin Shinawatra.
About 90 people were killed and nearly 1,900 were wounded in a series of street clashes between demonstrators and security forces, which culminated in a bloody military crackdown and the arrests of the movement's leaders.
The Reds were demanding immediate elections, accusing the government at the time of being undemocratic because it took office in 2008 through a parliamentary vote, after a court stripped Thaksin's allies of power.
The judge postponed the first hearing until December 13 because a lawyer for Red Shirt militant leader Arisman Pongreungrong said his client could not attend the trial due to food poisoning.
"The court will only allow this one postponement," the judge said, as hundreds of police stood guard outside the court.
Arisman drew international attention when he narrowly avoided capture by police commandos in April 2010 by climbing out of the third-floor window of a Bangkok hotel in front of the media.
He surrendered last year after almost 20 months on the run.
The leaders pleaded not guilty in August 2010 to terrorism charges. Hearings can only be held when parliament is not in session as sitting lawmakers have immunity.
The Red Shirt leaders, most of whom surrendered to police after the government sent in armoured vehicles and troops firing live rounds, deny they incited their followers to cause violence.
"I'm certain that the protesters did not need any speeches to provoke them. They saw more and more people injured and dying. The situation was already very heated," Red Shirt leader Nattawut Saikuar, now deputy commerce minister, told AFP ahead of the hearing.
After the crackdown, protest leaders asked their supporters to disperse, but authorities accused hardcore demonstrators of setting fire to dozens of buildings, including a shopping mall and the stock exchange.
No government or military officials from the time who oversaw the army operation have been charged over the deaths of protesters, prompting accusations by the Red Shirts of double standards.
Thaksin, adored by many poor Thais for his populist policies while in power, was toppled by royalist generals in a 2006 coup that unleashed years of street protests by the Reds and the rival royalist Yellow Shirts.
Elections in 2011 brought Thaksin's Red Shirt-backed Puea Thai party to power and swept his sister Yingluck into office.