He was friends with Alec Guinness, who helped him obtain his role in Star Wars; they had met during a production of Richard II decades prior. Like Guinness, Jordan was a member of the fabled Old Vic acting company; when he died in 2020, he was the last surviving actor.
Although his role as Cass was arguably his most famous, Jordan also featured in a number of other prominent films, including The Battle of the River Plate (1956) and Too Late the Hero (1970).