Noble One


 * In nautical parlance, Number One is also a term of address used by a commanding officer to refer to their executive officer.

"I need you in that fight, Number One... Number One, come in... Number One, do you read me?"

- Unknown UNSC commanding officer

Number One (true name unknown) was the term of address for an unknown person involved in the Battle of Reach.

In the Halo: Reach announcement trailer, Number One is repeatedly hailed by his/her commanding officer, but does not respond: eventually, the transmission is interrupted when SPARTAN-259 calls the officer.

It is possible that Number One was killed during the Battle of Reach, left or deserted the battle or was otherwise incapacitated. It is also possible that SPARTAN-259 is the person being referred to as 'Number One'.