Originally intended to be called The Fighting Tigers, Dad’s Army was based partly on co-writer and creator Jimmy Perry’s real-life experiences in the Local Defence Volunteers (later known as the Home Guard). Perry had been 15 years old when he joined the 19th Hertfordshire Batallion and with a mother who did not like him being out at night and fearing he might catch cold, he bore more than a passing resemblance to the character of Frank Pike. An elderly lance corporal in the outfit often referred to fighting for Kitchener against the "Fuzzy Wuzzies" and proved to be a perfect model for Jones. Other influences were the film Whisky Galore!, and the work of comedians such as Will Hay whose film Oh, Mr Porter! featured a pompous ass, an old man and a young man which gave him Mainwaring, Godfrey and Pike. Another influence was Robb Wilton.

Perry wrote the first script and gave it to David Croft while working as a minor actor in the Croft-produced sitcom Hugh and I, originally intending the role of the spiv, Walker, to be his own. Croft was impressed and sent the script to Michael Mills, Head of Comedy at the BBC. After addressing initial concerns that the programme was making fun of the efforts of the Home Guard, the series was commissioned.

In his book, Dad's Army, Graham McCann explained that the show owes a lot to Michael Mills. It was he who renamed the show Dad's Army. He did not like Brightsea-on-Sea so the location was changed to Walmington-on-Sea. He was happy with the names for the characters Mainwaring, Godfrey and Pike but not with other names and he made suggestions: Private Jim Duck became Frazer, Joe Fish became Joe Walker and Jim Jones became Jack Jones. He also suggested adding a Scot to the mix. Jimmy Perry had produced the original idea but was in need of an experienced man to see it through. Mills suggested David Croft and so the successful partnership began.

The show was set in the fictional seaside town of Walmington-on-Sea, on the south coast of England (although the external scenes were mostly filmed in and around Thetford, Norfolk.^[4]) Thus, the Home Guard were on the front line in the eventuality of an invasion by the enemy forces across the English Channel, which formed a backdrop to the series. The first series had a loose narrative thread, with Captain Mainwaring’s platoon being formed and equipped—initially with wooden guns and LDV armbands, and later on full army uniforms; the platoon were part of the The Queen's Own Royal West Kent Regiment.

The first episode, "The Man and the Hour," began with a scene set in the 'present day' of 1968, in which Mainwaring addressed his old platoon as part of the contemporary 'I'm Backing Britain' campaign. The prologue opening was a condition imposed after initial concerns by Paul Fox, the controller of BBC 1, that it was belittling the efforts of the Home Guard.^[5] After Mainwaring relates how he had backed Britain in 1940, the episode proper began; Dad’s Army is thus told in flashback, although the final episode does not return to the then-present. Later episodes were largely self-contained, albeit referring to previous events and with additional character development.

Since the comedy was in many ways dependent for its effectiveness on the platoon’s failure to participate actively in World War II, opposition to their activities had to come from another quarter, and this generally showed itself in the form of Air Raid Precautions (ARP) Warden Hodges, although sometimes the Verger of the local church, or Captain Square and the neighbouring Eastgate Home Guard platoon. However the group did have some encounters related to the war such as downed German planes, a U-boat crew, parachutes that may have been German, and German mines.

The humour ranged from the subtle (especially in the relationship between Mainwaring and Sergeant Wilson, who also happened to be his deputy at the bank) to the slapstick (the antics of the elderly Jones being a prime example). Jones had several catchphrases, including "Don’t panic!", "They don’t like it up ’em", "Permission to speak, sir", and talk about "the Fuzzy-Wuzzies". Mainwaring said "Stupid boy", in reference to Pike, in many, if not most episodes. The first series occasionally included darker humour, reflecting the fact that, especially early in the war, members of the Home Guard were woefully under-equipped and yet still prepared to have a crack at the German Army. A poignant moment to this theme occurs in "The Battle of Godfrey’s Cottage" episode, during which the platoon believes an invasion to be taking place. Mainwaring and a few volunteers decide to stay in the village to hold off any German advance so information can be relayed back by the rest of the platoon; "Of course, that will be the end of us!", says Mainwaring. "We know sir", replies Frazer, before getting on with the task in hand.

ARP Warden William Hodges Played by Bill Pertwee
Mainwaring's greatest enemy - the local greengrocer with dirty fingernails who by night becomes the local Chief Air Raid Warden, ordering all and sundry to "Put that light out!". A 'common little man' according to both Mainwaring and Wilson, he would do his upmost to get one over on the platoon, even going as far as rowing out into the darkness to reprimand them for showing a light. He regularly teams up with the vicar or the verger against the Captain. There is slight friction between Hodges and Wilson, as he is Mrs Pike's landlord, and has, on occasion has taken her out for a drink - or two. Although showing signs of cowardice, there is no doubt that he would stand up against the Nazis would the occasion had arisen. Hodges served in the army during the last campaign and acted as a guard in a prison camp, where he managed to learn German, and is well respected in the town as their best bowler on the cricket team. He is aided in his shop by Mabel.