The new series comprises four two-hour films; Trove, Nocturne, Sway, and Neverland which have been written by Morse contributor, Russell Lewis.
Author Colin Dexter, whose first Morse story was published in 1975, continues his association as series consultant.
Discussing the new stories, Lewis said: “1966 brings Endeavour a fresh quartet of baffling mysteries set to test his brain and body to breaking point.
“Though offset by the possibility of love unlooked for, against a backdrop of growing change in Britain and the wider world, Endeavour must face a challenge that threatens to take from him all he holds dear… Family. Friends. Colleagues. The old order changeth… but not without a fight. To the death.”