A Company

''This article is about the Marine Unit. For the Halo Costuming Community Website, see 405th.com.''

The 405th is a UNSC Marine Corps unit of unknown size. Stationed at Diego Garcia, it was among the first UNSC forces to respond to the Covenant's invasion of Mombasa, Kenya during the Battle of Earth.

Background
The 405th is based out of Diego Garcia. They arrived on scene during the Battle of Earth in Mombasa, Kenya on Earth. They went on to fight in the city streets of New Mombasa.

History
The 405th assisted SPARTAN-117 in the destruction of a Scarab that was moving through the city. Surviving members of this unit then traveled to Installation 05 along with SPARTAN-117 aboard the. It is assumed all were killed in either the Battle of the Quarantine Zone or, although unlikely, the First Battle of High Charity. It is also possible that they were attacked by the Flood as some of the Combat Forms spilled out on the In Amber Clad.

Personnel
Known members of this unit include:
 * Staff Sergeant Banks
 * Corporal Perez
 * Private McKenzie

Trivia

 * If Staff Sergeant Banks was in command of A Company, as Corporal Perez says, that means that all of the officers in the 405th had been killed.
 * The 405th is also an online community that creates Halo armor.