Believed to be the first to develop the concept of dungeon exploring associated with Gary Gygax's early game group Castles and Crusades society. Co-authored the first set of OD&D rules in 1973 with E. Gary Gygax.
Arneson became employee at TSR in 1976 (from: Silver Anniversary History Booklet).
For more information please refer to the History of TSR section.
For additional information, refer to Dave Arneson's homepage.
Picture taken from 2003 GenCon program.