Commodore Cohen was a Starfleet flag officer serving in the 23rd century. In 2269, Commodore Cohen was the commanding officer of Starbase 25 when the USS Enterprise (NCC-1701) docked at the station for ten days of shore leave. During this period, Vice Admiral Lori Ciana travelled to the facility in order to consult Cohen on the plans to begin Federation colonization efforts in the sector. (TOS novel: Allegiance in Exile)