STUTTGART, Germany (Reuters) -The men accused of plotting a violent coup against the German state were well advanced in their plans to establish a nationwide military structure to crush any opposition to their putsch when the authorities swooped, a court heard on Monday.

Their willingness to use violence was shown by the way one of their number, gun enthusiast Markus L., unleashed a hail of bullets on policemen arriving to arrest him, causing one of them life-altering injuries, prosecutors said.

The nine men on trial are part of a network of 27 people, subscribers to the esoteric Reichsbuerger - 'citizens of the Reich' - belief system, whom prosecutors accuse of seeking to install an aristocrat as Germany's ruler.

The hearing marks the start of three marathon trials of 27 people in total accused of conspiring in a plot foiled by authorities at the end of 2022.

Filing into the maximum security courtroom in Stuttgart, the nine suspects, some wearing fleeces, others in shirts, looked glum as they took their seats behind thick panes of glass separating them from their lawyers, though some were buoyed by seeing smiling family and friends in the public gallery.

The suspects in one of the largest criminal cases in German history had been held incommunicado until they met in the courtroom, being housed in detention centres all over southwest Germany. Some had been roused long before dawn for the long journey to the courtroom, where they occasionally dozed.

Monday's trial focuses on nine suspects whose alleged role was to arrange local military cells that would crack down on any resistance to the coup.

'DEEP STATE'

Prosecutors said the plotters believed the modern German state to be ruled by a shadowy 'Deep State' which, among many crimes, detained and tortured children. The group believed it would have the support of a supposed Alliance, including the U.S. and Russian governments, if it toppled what they saw as an illegitimate German government.

"They were convinced that the German population would back them once they knew what was going on," a prosecutor said. "They were aware that their plans would involve violence."

All nine suspects contest the charges against them.

Germany's domestic intelligence service (Verfassungsschutz) put members of the Reichsbuerger movement under observation in 2016. It says the group encompasses some 21,000 people and does not recognise modern-day Germany as a legitimate state.

The political leadership of the group on trial, led by real estate investor Heinrich XIII Prinz Reuss - scion of a now throneless dynasty - will appear in court in Frankfurt next month, while another group of suspects including an astrologer stand trial in June in Munich.

Prosecutors described one of the suspects, Markus L., as waiting seated on a sofa for officers climbing the stairs to his apartment before letting off 10 rounds with a home-built machine gun. He faces charges of attempted murder.

The nine had stored up 500,000 euros in cash alongside 380 guns, 350 bladed weapons and some 148,000 rounds of ammunition.

'HATRED FOR OUR DEMOCRACY'

Reichsbuerger tend to believe they are citizens of an earlier Germany - typically the pre-World War One German Reich - which has been usurped by today's Federal Republic.

"These militant Reichsbuerger are driven by hatred for our democracy," interior minister Nancy Faeser said on Sunday. "We will continue our crackdown until these militant structures have been fully exposed and crushed."

The Reichsbuerger have parallels to, and are partially inspired, by groups such as the QAnon movement in the U.S., where conspiratorial theories about a Deep State helped fuel the Jan. 6, 2021 storming of the Capitol in Washington D.C.

Judges have scheduled hearings in the Stuttgart case until January 2025, but given the complexity of the case and the number of witnesses and suspects, experts believe it could run for much longer, possibly even for several years.

The last comparable trial - involving members of the far-right National Socialist Underground which murdered 10 people, mostly ethnic Turks - lasted five years.

(Reporting by Thomas Escritt; Editing by Friederike Heine, Hugh Lawson and Gareth Jones)

By Thomas Escritt