Hi Sam,
CIDOC/CRM is the ontology of choice for Structured History
as it is anchored on modelling events.
An excellent project based on it is the ResearchSpace from
the British Museum.
See:
http://www.researchspace.org/
http://www.researchspace.org/home/rsandcrm
http://cidoc-crm.org/
Enjoy,
Dov