ITV broadcast a television film in the UK on 2 January 2012; in the United States, PBS aired it on 1 July 2012. It starred Shaun Evans as the eponymous police detective in his early career. Abigail Thaw, daughter of original Morse actor John Thaw, played the part of Dorothea Frazil in a scene at the Oxford Mail newspaper.
ITV commissioned a first series of four new episodes, filmed during summer 2012, and aired them from 14 April to 5 May 2013.
It was announced on 5 June 2013 that due to the success of Series 1, including consistently high ratings, ITV had commissioned a second series of four episodes. Filming commenced in Oxford in September 2013. On 24 September 2014, ITV confirmed that a third series of Endeavour had been ordered.
Before that third season of Endeavour screened on ITV, Evans told the Oxford Mail: "It's not like we have a six-year contract, there's none of that. It's day by day, year by year. I think this one is really good. We'll know when it airs if there's an audience for it and if we feel there's another place to take these characters."
In February 2016, ITV announced that a fourth series of Endeavour had been commissioned, which Roger Allam confirmed to Oxford Mail, with filming to begin in late spring 2016. To mark the 30th anniversary of Morse on television, the series will feature several early Morse characters and cameos by actors from the original series. The fourth series debuted on January 8, 2017 and it was announced the fifth season will be shown in 2018.
Set in mid to late 1960s Oxford, England, the series centres on the early career of Endeavour Morse (Shaun Evans) after he has left Lonsdale College of Oxford University late in his third year without taking a degree, spent a short time in the Royal Corps of Signals as a cipher clerk, and then joined the Carshall-Newtown Police. In the pilot episode, having been transferred to CID after only two years as a uniformed police constable, the young DC Morse soon becomes disillusioned with law enforcement and begins writing a resignation letter. Before he can resign, Morse is sent with other detectives from the Carshall-Newtown Police to the Oxford City Police's Cowley Police Station to assist in investigating the case of a missing fifteen-year-old schoolgirl.
Having studied at Oxford gives Morse advantages and disadvantages when dealing with Oxford's "town and gown" divide. During the pilot episode, he tenders his resignation but his superior, veteran Detective Inspector Fred Thursday (Roger Allam), the "guv" at the Oxford City Police's CID, sees in him an unblemished detective whom he can trust and takes him under his wing to be his new "bag man" meaning assistant, replacing a corrupt Detective Sergeant.
Series 1 begins with Morse transferring to the Oxford City Police in 1965 following a double-murder investigation that took place during the pilot episode. Morse is taken under the wing of Inspector Thursday. Thursday names Morse his designated "bag man" and shows him the ropes as Morse begins to solve a string of complex multiple-murders, much to the envy and annoyance of some of his superiors, particularly Detective Sergeant Jakes and Chief Superintendent Bright. Morse displays his obvious genius in solving intricate murders, including several with opera connections. Thursday and fellow officer, Police Constable Strange, try to steer the young Endeavour into taking his Sergeant's exam, so that he may be relieved of "General Duties" and become Thursday's official "bag man" with the appropriate rank and title. In the Series 1 finale, Morse is shot while attempting to apprehend a murderer and is placed on light-duty. At the same time, Morse comes to terms with the death of his cold and unfeeling father in December 1965.
Series 2 begins in 1966 with Morse returning to active duty at Cowley Police Station, after spending several months on light duty at Oxfordshire (County) Police's Witney Station, under the direction of D.I. Bart Church. Morse is received warmly by C.S. Bright and D.S. Jakes, as D.I. Thursday begins to keep a more watchful eye on the young Endeavour. As a result of the shooting, Morse begins to suffer from delayed stress and paranoia, as well as an increase in alcohol consumption. Upon return to active duty, Morse is confronted first by three cases, which he tries to tie in together. Morse makes several mistakes in the investigation, but despite his errors, he solves the cases, impressing his superiors. During the investigation he suffers a concussion after being struck over the head and is cared for by his nurse neighbour, Monica Hicks, in whom he takes an interest. At the same time, P.C. Strange enters into Freemasonry with many of Oxford's elite, and D.I. Thursday's daughter, Joan, begins to take an interest in Endeavour. During the course of several cases, pieces of circumstantial evidence go missing, and a murder suspect threatens Morse by claiming association with powerful men who will not take kindly to interference.
In the final episode, the looming merger of city and county police and misgivings about corruption, lead Thursday to consider retirement, in response to strong hints from C.S. Bright about age and health. Disheartened by this, Morse speculates to Monica about leaving the police and going abroad with her. Assistant Chief Constable Clive Deare asks Thursday and Morse to covertly investigate corruption within the police and council. Morse is sent to a rendezvous where he is ambushed by corrupt officers and Thursday is lured to Blenheim Vale, a derelict former wayward boys home, where there was rampant sexual and physical abuse (of which Jakes was a victim). Morse escapes the ambush and goes to support Thursday, who is shot by Deare, a participant in the abuse at Blenheim Vale. Deare tells Morse he has framed him for the murder of Chief Constable Rupert Standish. Deare is about to kill Morse when he is shot dead by a girl who had also been abused at Blenheim Vale, who then kills herself. Bright and Strange show up with backup and an ambulance. As Thursday is being loaded into an ambulance, Morse is arrested by officers from another force for the murder of Chief Constable Standish. The series ends with Thursday's fate unknown and Morse in a jail cell.
Series 3 begins in Spring 1967. D.C. Morse has been cleared of the murder of Chief Constable Standish and the records in the case of Blenheim Vale are sealed for 50 years. D.I. Thursday has been discharged from hospital, but the bullet could not be taken out of him and has resulted in recurring coughs. Monica has come to realize that she and Morse have gone their separate ways. Strange has been promoted to Sergeant and Morse considers his future after his time in prison, but with Thursday's encouragement, Morse returns to active duty investigating a murder following a disappearance at a funfair on Cowley Green. After solving a faked kidnapping and tainted fruit being sold at a local supermarket, D.S. Jakes retires from the Force and leaves Oxford. Strange takes Jakes' place as Detective Sergeant but assures Morse that they're still friends even though he's now his superior. Detective Inspector Thursday shows frequent signs of outbursts against suspects unwilling to co-operate during the investigations, and even uses violence as a way of extracting information. Although Morse is unsure about becoming Sergeant, Thursday assures him he's more of an Inspector.
In the final episode, Morse finally sits his Sergeant's exam and completes his paper well within the time allowed. An armed robbery takes place at a bank where Joan Thursday works and the armed robbers become trapped themselves along with Morse during an investigation into a killing and payroll robbery. After the robbers are arrested, Joan, emotionally affected by the ordeal, leaves Oxford for new pastures despite encouragement to stay from Morse. Realizing that Joan has gone, Thursday encounters Morse outside his house, and figures that he saw Joan leave. Thursday returns to his house and Morse follows him.
Noting that the series received upwards of 6.5 million viewers, Mark Sweeny writing in The Guardian stated that any decision to commission a subsequent series should be easy. Upon its American premiere, Los Angeles Times critic Robert Lloyd called it a "suitably complicated and pictorially engaging work of period suburban mystery."
Critics have been generally favourable, though even positive reviews have commented that the show's murder-mystery plots are occasionally unsatisfying convoluted puzzles or come to a "rushed, melodramatic and fairly preposterous conclusion."
A region 2 DVD of the pilot at 89 minutes long was released on 9 January 2012, but, as reviewers on Amazon.co.uk have noted, does not contain the full show and many scenes aired on ITV have been cut out. A complete edition running at 98 minutes was released on 26 January 2012.
Series 1 was released on DVD on 6 May 2013, Series 2 on 5 May 2014, and Series 3 on 1 February 2016.