There are at least two bands with the name Penance: 1) Band playing a mixture of doom, hardcore and thrash metal.
2) Band from London. 1) Penance was born from the ashes of Dream Death, when several members decided to pursue a more traditional doom direction. Dream Death existed during mid eighties and played speciphic mixture of doom, hardcore and thrash metal. Founders of Penance were drummer Mike Smail and guitarist Terry Weston (both previously a members of Dream Death) and they were the core of the band from its early days to the disbanding.

Read more about Penance on Last.fm.