Four men have been remanded in custody accused of inciting terrorism abroad and fundraising for terrorism.
Abu Izzadeen was one of six men charged
Abu Izzadeen, 32, Ibrahaim Abdullah Hassan, 22, Simon Keeler, 35, and Rajib Khan, 28, appeared at City of Westminster magistrates' court.
Shal Jalal Hussein, 24, and Omar Zaheer, 27, were remanded on bail accused of fundraising for terrorism.
The charges relate to speeches made at the London Central Mosque at Regent's Park in 2004.
Mr Hassan is also charged with possessing an article for the purposes of terrorism.
Mr Izzadeen, also known as Omar Brooks, became well known after being filmed heckling Home Secretary John Reid during a speech to Muslims last year.
The men were arrested in a series of raids in London and Luton.
Mr Izzadeen, Mr Hussain, Mr Keeler and Mr Hassan are all from east London. Mr Zaheer is from Southall, west London, and Mr Khan from Luton.
All the men are due to appear again on 18 May at the Central Criminal Court.