CTN 0452-9

Artificial Intelligence
Activation site:
Activation date:
November 7, 2549


A unique and incredibly powerful artificial intelligence (AI), Cortana was created by Doctor Catherine Halsey. A unique creation, Cortana achieved unprecedented levels of functionality, laying the groundwork for a wealth of advancements that ultimately paid huge dividends for the UNSC and humanity as a whole. In the case of Cortana, Halsey used tissue from her own flash-cloned brain as the foundation for the construct’s creation. While this practice was both illegal and considered by many as unethical, Halsey felt it was the best chance they had to achieve the desired results.

Operational history

The results were indeed remarkable, as Cortana became one of the most potent and valuable assets in humanity’s arsenal. She spent the first few years of her existence assisting Halsey within the confines of ONI’s CASTLE Base. In 2552, she saw her first real action as the UNSC prepared to move forward with the true purpose of Cortana’s creation, Operation: RED FLAG. Aiming for the capture of a high-ranking Covenant Prophet, RED FLAG paired Cortana with the SPARTAN-II super-soldier, Master Chief Petty Officer John-117. For the first time, she lived within the framework of his MJOLNIR power armor and his neural interfaces. The pair almost immediately became more than the UNSC had hoped for as together their strengths multiplied the other’s proficiency in often unpredicted ways.

While RED FLAG was never carried out due to the Covenant’s attack on Reach and UNSC’s eventual retreat to defend Earth, Cortana’s impact had just begun. Shortly before the fall of Reach, Dr. Halsey split a fragment off of Cortana to aid in deciphering vital information gleaned from a massive Forerunner artifact located beneath ONI’s Sword Base. The information Cortana uncovered proved vital to humanity’s survival against the Covenant. After the Covenant had begun their assault on the planet, Dr. Halsey employed Noble Team to reunite Cortana’s fragment with her primary presence with the Master Chief aboard the UNSC Pillar of Autumn. SPARTAN-III B-312 made the final delivery, and Cortana and the Master Chief made their escape off Reach, via a fateful slipspace jump that took them to the first discovery of the Forerunner ringworld known as Halo.

The discovery of this ancient installation, and subsequent surrounding events turned the tide in the conflict and brought victory in humanity’s war against the Covenant. Unfortunately, it also led to the reemergence of the Didact, an ancient Forerunner general with a long-held and vicious hatred of humanity. During a battle aboard the Didact’s ship, Mantle’s Approach, Cortana sacrificed her life to stop this new enemy, saving both the Master Chief and the Earth in the process.

Related Experiences


  • Halo: Combat Evolved Anniversary
  • Halo 2 Anniversary
  • Halo 3
  • Halo 4
  • Halo: The Master Chief Collection
  • Halo: Reach


  • Halo: The Fall of Reach
  • Halo: The Flood
  • Halo: First Strike
  • Halo: Ghosts of Onyx


  • Halo: Legends
  • Halo: Forward Unto Dawn

Related Products

Cortana Chip Keychain

Keep Cortana close with this sculpted data chip keychain.

Halo 2 Master Chief Play Arts Kai Figure

Square Enix lets you display your love for the award-winning Halo franchise with your very own Halo 2 Master Chief Play Arts Kai figure.