I heard the drums roll and then saw these gentlemen marching by. Who are they? The sashes and banners say Martyrs, from various places, Essex, Kent, Medway. I found a little information from a google search that tells of a protestant martyr burned to death in 1555, for not attending a catholic mass, then I found contradicting information, saying those who were catholics were the martyrs.
I'm still none the wiser as to the organisation represented here.
I can tell you though they were not keen on being photographed. Come on guys if you are going to march through the streets of London dressed like this and banging drums, expect to be photographed.