It could be great to visualize both the family tree and a timeline. The timeline would show every event related to the persons drawed, and aldo would be able to import "personalized" events, i.e. historical world, national, local events, etc.
just a simple timeline... whre people's pic in placeholder on a normal timeline graph...the other would be... to have it still in "family tree" look...but stretched out over time.... the criss crossing lines might get to be challenging. but the MH team is always up for those :)