The chance discovery of the gang, the National Socialist Underground (NSU), which had gone undetected for more than a decade, has forced Germany to acknowledge that it has a more militant and dangerous neo-Nazi fringe than previously thought.
Beate Zschäpe, 38, is charged with complicity in the shooting of eight Turks, a Greek and a German policewoman in towns across Germany between 2000 and 2007, as well as two bombings in immigrant areas of Cologne and 15 bank robberies. Her two presumed male accomplices both committed suicide in 2011.
In a tailored black suit, white blouse and big earrings, and with her long hair looking glossy, Zschäpe's appearance in court was very different from the surly mugshots that have been splashed over German media ahead of the eagerly-awaited trial. One of four other defendants charged with assisting the NSU hid under a dark hood.
Defence lawyers immediately challenged the presiding judge's impartiality for ordering them but not some other participants to be searched thoroughly before entering the Munich court.
"This implies the defence lawyers are so stupid they might bring forbidden objects into the court," said attorney Wolfgang Stahl, adding that Judge Manfred Götzl seemed to suspect the defence team might pass messages or objects to their clients.
The case has shaken a country that believed it had learned the lessons of the past, and has reopened a debate about whether it must do more to tackle racism and the far right.
"With its historical, social and political dimensions, the NSU trial is one of the most significant in post-war German history," lawyers for the family of the first victim, flower seller Enver Simsek, said in a statement.
Outside the courthouse, which was guarded by about 500 police officers, German-Turkish community groups and anti-racism demonstrators held up banners including one that read: "Hitler-child Zschäpe, you will pay for your crimes".
The existence of the gang came to light in November 2011 when the two men believed to have founded the NSU with Zschäpe, Uwe Mundlos and Uwe Böhnhardt, committed suicide after a botched bank robbery and set their caravan ablaze.
In the charred vehicle, police found the gun used in all 10 murders and a grotesque DVD claiming responsibility for them, in which the bodies of the victims were pictured with a cartoon Pink Panther totting up the number of dead.
After the suicides, Zschäpe is believed to have set fire to a flat she shared with the men in Zwickau, in east Germany. Four days later, she turned herself in to police in her hometown of Jena, saying: "I'm the one you're looking for."
For the victims' families, the trial will be the first chance to come face-to-face with Zschäpe, whose blank expression and resolute silence since her arrest have left people struggling to make sense of her motives.
"The Banality of Evil" read the front page of the newspaper Die Welt. The mass-circulation Bild wrote that Zschäpe "looks like a woman at the supermarket till" rather than someone "rabidly mad or explosive".