Marquis was the original name for the Marriott Rewards program. Sometime during the late 1990s, Marriott began combining their various frequent stay programs (Marquis, Courtyard Club, etc.) into one big program. Around 2000, they formally came out with their current program, Marriott Rewards.

Gold Marquis was the first level elite status. Basically equivalent to Silver elite status today. If you want to know more about Marriott's old rewards program(s), you can do a search on 'Marquis' in this forum.