Billed as the first chapter of a brand new Halo saga that will no doubt span multiple Xbox console generations, it's the first Halo game not to be developed by series creator Bungie.
Microsoft studio 343 Industries is now in the hot seat, and it has promised to address the unanswered questions around the fates of the series' protagonist, Master Chief, and his artificial intelligence companion Cortana.
Set four years after the events of Halo 3, "Master Chief returns to confront his destiny and face an ancient evil that threatens the fate of the entire universe", according to the publisher.
Microsoft Studios corporate vice president Phil Spencer said: "We are beginning a new saga with Halo 4 and embarking on a journey that will encompass the next decade of Halo games and experiences.
"Millions of fans worldwide have been eagerly awaiting the opportunity to step back into the boots of Master Chief, and with Halo 4 leading the charge, we're confident 2012 will be the most successful year in Xbox history."
343 Industries recently told us it already has "a definite story arc in mind" for Halo 5 and 6.