2549

• Paris IV is attacked. Staff Sergeant Avery Johnson gets an encounter with max dosage of radiation after using a box of Plasma Grenades and becomes diagnosed with Boren's Syndrome, which in the future will save his life from Flood infection on Installation 04 and onward. It is possible that the Borens' Syndrome story involving Johnson is a hoax, based on the account described on page 122 of the Halo Graphic Novel.
• The 2549 edition of the Hog is probably released, although it could have been late in 2548.
• The Covenant recall their standard Type-25 Wraith model to update its design, fitting a Type-52 DESW on a ring mount.
• Some time this year, the SPARTAN-II Program has been announced to the public, and any Spartans who die are to be listed as ether Missing In Action or Wounded in Action, to give the illusion that Spartans never die .

September

• September 9: Second Battle of Arcadia. The Covenant glasses Arcadia.

November

• November 7: Cortana is created from Dr. Catherine Halsey's flash-cloned brain.