Duke named after the Duke of Sodor and originally The Duke is considered a hero amongst the engines.
Duke was built at Boston Lodge in Minfford, Wales in 1879 before being transported to Sodor for the Mid Sodor Railway's grand opening in 1880. He was named after the Duke of Sodor and calls him "his grace" as Duke usually says to Stuart and Falcon "that will never suit his grace" which they grew tired of it. He told them about Stanley who rode carelessly and causing accidents enraging the Mid Sodor Railway's manager to turn him into a generator behind their shed. In 1947, the Mid Sodor Railway closed down due to flooding in a lead mine. No one wanted Duke and some men brought Falcon and Stuart instead.
Duke remained in his own shed, wondering about his grace known as Lieutenant Colonel Robert Charles Norramby who served in the Sodor Regiment, and was killed by the retreating German and Italian armies in North Africa before their surrender to British and American forces in May 1943.
A landslide later covered Duke's shed with trees around it and no one, even the Duke of Sodor knows that an engine is still inside that shed. In 1969/70, Reverends Awdry and Boston travelled to the former Mid Sodor Railway with Mr. Fergus Duncan, the controller of the Arlesdale Railway. Reverend Boston fell in through the roof and founded Duke. The engine was taken by both road and rail to Crovans Gate where he was eventually restored and returned to service in 1983, two years before Great Little Engines was published in 1985.