A Company

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

The 405th is a UNSC Marine Corps unit in excess of a company in 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.

History
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.

Elements of the 405th's A Company assisted John-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 John-117 aboard the. It is likely all were killed in either the Battle of the Quarantine Zone or, although unlikely, the 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:
 * Unidentified lieutenant
 * Staff Sergeant Banks
 * Corporal Perez
 * Private McKenzie