Cortana

“Keep your head down, there’s two of us in here now.”
Cortana to Master Chief

Biographical information
Began service ≤2550/09/04

Physical description
Gender: Female AI programming

Description: Tall and slender with short-cut hair in Halo: Combat Evolved, then long hair in Halo 2 and Halo 3

Normal Color:

• Normal: Blue/Purple, Green while inside Alpha Halo’s central computer
• Angry: Pink/Green
• Flattered: Pink

Political information and functions
Affiliation: United Nations Space Command

Primary Function: Software Infiltration, Capture of a Covenant Prophet, Assisting the Spartans

Notable Battles:

• Battle of Reach
• Battle of Installation 04
• Second Battle of Reach
• Battle of Eridanus Secundus
• First Battle of Earth
• Battle of Installation 05
• Destruction of Installation 04 (II)

Cortana, UNSC Artificial Intelligence serial number CTN 0452-9, is a “smart” AI construct, or “Intelligent Agent“. She was one of the most important figures in the Human-Covenant War, and served as John-117’s partner in various combat missions, as well as serving as the AI for the United Nations Space Command Halcyon-class Cruiser Pillar of Autumn and the Orbital Defense Platform Cairo Station. In addition, she held vital data pertaining to the Halos, including the Activation Index from Alpha Halo.

Content Source: halo.wikia.com