Arthur L. Mason was a Starfleet fleet admiral who served as chief of staff at Starfleet Command in the mid-23rd century. Admiral of the Fleet Mason transmitted orders to James T. Kirk on stardates 6289 and 6291 in the 2260s, requesting copies of key log entries from the senior staff of USS Enterprise. (TOS comics: "The Key Collection, Volume 1", "The Key Collection, Volume 2") Mason's orders were shown on the back cover of the comic book collected editions.