Microsoft has announced that the Halo series has sold more than 65 million copies worldwide, which is 5 million more than Microsoft announced in October 2004 for the launch of Halo: The Master Chief Collection.
The series started in 2001, with the launch of the first Halo game: Halo: Combat Evolved. Unit sales for each game in the franchise have not all been revealed, however the last numbered release was very successful. Halo 4, was released in 2012, was the best selling Microsoft Studios Game of all time at the time of its release, and sold more in its first year than Halo 3 in the year following its release.
The latest game in the Halo series will be released later this year, with Halo 5: Guardians. 343 Industries recently released a ViDoc discussing their aspirations for the next Halo game.
Halo 5: Guardians will be released for the Xbox One on October 27, 2015.