Armory's own site records that "In early 2011 Alan Reiner started building" the wallet, and describes the design he arrived at as splitting client functionality between network security and wallet security. That split is what an offline signing wallet is: one machine that talks to the network and holds no keys, one machine that holds keys and never talks to anything.
The same page lists him as chief executive and founder of Armory Technologies, Inc., and states that before Bitcoin he spent seven years at the Johns Hopkins University Applied Physics Laboratory working on real-time image and video processing. He created the BitcoinArmory repository on GitHub on 19 November 2011 under the handle etotheipi.
The project's current credits page, maintained by the developer who took it over, lists him as "Project Creator and Former Project Lead" and records that Armory Technologies is no longer participating. He has not been involved in the software since the handover in February 2016.