Complex sentence: There was a number of rifts in the IAWM, most damagingly in 2004 when PRO (and chairperson of the Cork Anti-War Campaign) Dr Fintan Lane resigned, this caused a number of groups and members to leave the organisation.
Split into simpler sentences: There was a number of rifts in the IAWM, most damagingly in 2004 when PRO (and chairperson of the Cork Anti-War Campaign) Dr. Fintan Lane resigned. This caused a number of groups and members to leave the organisation.