From Halopedia, the Halo wiki
Paul Russel was an employee of Bungie who served as an Environmental Artist for Halo: Combat Evolved, Halo 2, Halo 3, Halo 3: ODST and Halo: Reach. He was born in 1967 in Chicago, Illinois, USA. He lived there until moving to Washington state. Russel came up with the series title "Halo", and has been said to be "The father of Halo". He is largely responsible for the Forerunner and human military architectural styles and decoration in the Halo series, including what is now known as the Eld symbol. This has led to him being nicknamed "the Forerunner guy", although he dislikes this epithet.
Russel left Bungie in August 2010 after working there for 11 years and joined Certain Affinity in May 2011, where he worked as Senior Environment Artist. Russel left Certain Affinity in May 2012 and in November of 2012 became owner and CEO of Spazdesign.