On a private voyage of exploration between 1792 and 1794, Captain John Hayes with two ships, the Duke of Clarence and the Duchess, spent several weeks in Southern Tasmania, during which time he named the Derwent River and also Risdon Cove. John Hayes also named Mount Direction.
Clarence Plains, now known as Rokeby, was named by Hayes in 1793 after his ship The Duke of Clarence. From this early name came the name of the present city. Rokeby itself was named after George Stokell's Rokeby House which Stokell had named after a village in Yorkshire, England.