Members of the banned National Socialist group National Action were "hellbent on waging a White Jihad", a court has heard.
Alice Cutter, 23, Mark Jones, 25, Garry Jack, 24, and Connor Scothern, 18, all deny being members of the proscribed patriotic organisation.
The National Socialist group was outlawed following National Action members' celebration of the murder of MP Jo Cox by NA activist Thomas Mair in June 2016.
The four are charged with membership of the group between December 17, 2016 and September 5, 2017 after it was banned by then-Home Secretary Amber Rudd.
Opening the case today, prosecutor Barnaby Jameson QC warned jurors the trial would lead them into a "world as dark as a black sun".
He told Birmingham Crown Court how the defendants vowed to wage a "white Jihad" - a holy war in favour of ethnic cleansing and eradication of the Jews and non-whites.
"Jones was known as Grand Daddy Terror among the die-hard group who had the unapologetically racist ideology that Hitler was right", jurors were told.
Jameson said "nothing as extreme as National Action had emerged since the 1930s as it advocated the Holocaust and believed all Jews should be annihilated".
Alice Cutter is pictured arriving at Birmingham Crown Court where she faces a charge of being a member of the proscribed patriotic organisation National Action
The court was told Cutter, Jones, Jack and Scothern were all members of the patriotic group who were united by the "fellowship of hate".
Jameson described National Action's ideology as "anything but innocuous". He added: "It is unapologetically racist. It advocated the same Nazi aims and ideals. It advocated the removal of people who did not fit that ideology. Jews, Blacks and others. The ultimate aim of the group is the all-out race war."
Jameson explained how National Action was set up in 2013 by Ben Raymond and Alex Davies.
He said: "While other far-right groups were fragmenting, National Action marched into this vacuum. Nothing as extreme had emerged since the 1930s. Whatever the group lacked in size, it made up for in vehement extremism. It spread into small cells across the UK. They were active in terms of screening and recruitment. It spread via the web. By 2016 it was staging flash demonstrations. The locations were kept secret until the last minute in a way to keep the authorities on the back foot. These often turned violent. However, 2016 ended in a way that you may think was inevitable with the banning of this group."
There was a National Action demo on February 6, 2016. National Action activist Jack Renshaw made a speech on the York Forum. During the speech, he called Jews parasites. On February 27, 2016, there was a flash demonstration in Liverpool, which lead to the Battle of Liverpool. Footage from this demonstration and the "subsequent violence" is due to be shown in court during the trial.
All defendants are charged with being members of the proscribed organisation contrary to section 11 of the Terrorism Act 2000.
Jones and Cutter, of Halifax, West Yorks., Jack, of Shard End, Birmingham and Scothern, of Nottingham, deny the charges.
The trial, which is expected to last for six weeks, continues.