April 29, 2010 was when they announced the 10 year partnership with Activision.i still dont understand the details of that deal. and i still dont get why MS didnt let them do something new, i mean if its lose bungie or let them do something new... then let them do something new.
October 1, 2007 was when Bungie split from Microsoft but they were still in contract to make more Halo games.