Patrice Désilets designed the original Assassin's Creed series concept that grew from a Prince of Persia project.
Désilets was the creative director of Assassin's Creed and had previously worked on Prince of Persia: The Sands of Time. During early development, the team explored a Prince of Persia game centered on a hidden protector serving a prince. That idea evolved into a new property about assassins, historical conspiracies, and the relationship between a mentor and a young leader.
The resulting game became Assassin's Creed, released by Ubisoft in 2007. Désilets is therefore closely linked to the franchise's original creative direction, although a large Ubisoft team contributed to its design, technology, writing, art, and production.
Jade Raymond is often associated with the first game because she served as its producer, while Yannis Mallat was a senior Ubisoft executive connected to the Montreal studio. Those roles are different from the creative-director role. The franchise later changed leadership and structure across many sequels, but its initial concept is most specifically associated with Désilets.