This is an alleged coup plot featuring German nobility, a 'massive arsenal' and the belief that Queen Elizabeth II's death may have been a secret 'signal' to take action.
Trials are underway for people allegedly involved in the so-called Reichsbürger movement, with those accused of being ringleaders expected to appear before a judge.
The conspirators are said to have planned to violently overthrow the German government.
Investigators claim the conspiracy theorists believed the country was run by a “deep state.”
Tuesday's hearing in Frankfurt is the highest profile of three trials following the nationwide raids in 2022.
The case is considered extremely important due to its scale and the potential insights it could provide into far-right networks.
The Reichsbürger, or citizens of the Reich, were a loose and heterogeneous group that denied the legitimacy of the modern German state. Some even claim that the country was established by the victorious Allied forces after World War II.
Domestic intelligence estimates that around 23,000 people follow the movement, which displays “anti-Semitic attitudes” and a “high affinity” for weapons.
People associated with the Reichsbürger say the armed group planned to enter the Berlin parliament and arrest lawmakers on the so-called “Day X”.
According to the indictment, there was discussion about whether the death of the late Queen Elizabeth II was a “signal.”
Much of the attention in the trial will focus on Prince Henry XIII Reuss, a descendant of the noble Reuss family and a real estate developer from Frankfurt.
The 72-year-old is said to hold meetings of the group's 'central council' at his home in East Germany and be appointed 'head of state' if the coup is successful.
According to the indictment, he was responsible for negotiating a peace treaty with the Allies and appeared at the Russian consulate in Leipzig as part of an attempt to contact Moscow.
Also standing trial is Birgit Malsack-Winkemann, a former judge and member of parliament for the far-right Alternative for Deutschland party.
Prosecutors said she used her access to council property to “smuggle” co-conspirators to scout the area and was responsible for the legal department of the group's central council.
Their plan to reorganize Germany's political structure would have included taking over institutions at the state and local levels. Members reportedly knew this “had to do with killing people.”
The 'Council' would act as the central body, while the 'Military Corps', made up of 286 units, would enforce the new order throughout the country.
Prosecutors said the group had access to a “large arsenal” including guns, ammunition, night vision devices and handcuffs.
According to the indictment, the association also had financial resources of approximately 500,000 euros.
Over time, members are said to have become 'increasingly isolated' from the outside world.
Jan Ratje, a senior researcher at extremism watchdog CeMAS, said the conspiratorial and sovereigntist movement arose from the desire of some former Nazis to rebuild the Nazi German Reich.
He says the Reichsbürger movement, with its violent and far-right traditions, has been dangerously underestimated.
“People always thought these were crazy people writing crazy letters to the government,” he adds.
Mr Rathje said that even if the coup attempt had not succeeded, people could still have suffered serious harm.
“On a symbolic level, this would be successful because it would allow radicals to attack the government in a violent way, fostering the idea that the government is weak.”
The trial, which has been divided into three due to the scale of the case, is taking place in Stuttgart, Frankfurt and Munich.