Cortana is a fictional character featured in the video games Halo: Combat Evolved and Halo 2.

Background

Cortana is a "smart" artificial intelligence, which grants her the ability to learn and adapt, but also leaving open the possibility of Rampancy. She was constructed from the cloned brain of Dr. Catherine Elizabeth Halsey , the creator of the SPARTAN project . Her primary mission was to assist the SPARTANs in the capture of the Covenant High Prophets, and then to "negotiate" either a truce or peace treaty.

Cortana has no physical form, such as 343 Guilty Spark's avatar. However, she maintains the ability to communicate a strong female voice through available communications systems, and, if possible, project a holographic image of herself. Originally, the chosen image is that of a female human with short hair; her skin is composed of purple energy. Later, she adapts to a similar figure, but with longer hair.

Originally, the core of Cortana was contained in a disk, which can be inserted to most any system; later upgrades, however, provide her with the ability to enter any system by merely touching it. Cortana was designed to infiltrate any security system, and once she is physically inside, there is little that can stop her from taking absolute control.

Aside from that, she is very proficient in the coordination and use of UNSC and later Covenant military hardware. Because the UNSC's primary use of artificial intelligence is to oversee the targeting of point-defense weaponry used in space battles, Cortana can operate ships and space stations by herself. But, for Cortana at least, this is only a secondary function.

Cortana has a smart, witty personality, and a good sense of humor. She has hardwired loyalty to humanity and the UNSC, but seems to be genuinely loyal in any case.

Trivia

• Cortana is voiced by actress Jen Taylor in both Halo: Combat Evolved and Halo 2.
• Cortana is named after Edward the Confessor's legendary Sword of Mercy, the tip of which was, according to the legend, broken off by an angel to prevent a wrongful killing. This follows Bungie's trend of naming A.I.s after legendary/mythological swords, particularly in the Marathon series.

Quotes

• "Keep your head down! There's two of us in here, remember?"
• "If I still had fingers, they'd be crossed..." (during escape pod descent to Halo in the first game)
• "Unfortunately for us, I like crazy!" (during final cutscene of level 1 of Halo 2)
• "I have the Index. You can just float and sputter!" (to 343 Guilty Spark)
• "Halo isn't a cudgel, you barbarian!"
• "Oh, I'm sorry. Were you killing something?"
• "Thanks for the tank, he never gets me anything" (when Johnson arrives with a tank for Master Chief to use in Halo 2)
• "You look nice"
• "If I were a megalomaniac, which I'm not, that's where I'd be."