Will Butley
From Tardis Wiki, the free Doctor Who reference
Will Butley was a patient at the Huang Ti Clinic. Born in the 17th century, he found the secret to long life while in the East Indes Company. This allowed him to live for ~300 years - although by this time he was essentially in his 90s.
He often was walked around the clinic by Ron Sharpe. He knew the incantations that created the liquid that kept people young. (AUDIO: The Tao Connection)