Martha was present in the second of the two dry runs made in November 1960, where she was played by fellow Welsh-born actress Doris Hare.
Her relative youth compared with her co-stars was obscured by the character's wardrobe, with Martha normally wearing a hairnet, beret, spectacles, and an old mackintosh, all of which were provided by Carol who bought them second-hand in a jumble sale.
Over time, they got stories of their own, notably Martha's attempts to effect a relationship with her old school friend Ted Ashley (Jerold Wells).
Martha accepted but only lasted a few days as Ena's suspicious nature led her to walk out of hospital and return to her vestry, senile decay or not.
In March 1963, Martha was taken on by Jack (Arthur Leslie) and Annie Walker (Doris Speed) as the new Rovers Return Inn cleaner, and she also worked in the same capacity at Laurie Fraser's (Stanley Meadows) Viaduct Sporting Club the following year.
The catalyst was the return of Ted Ashley (Jerold Wells), a former classmate at Bessie Street who had long since emigrated to Australia and made a good life for himself as a farmer and shopkeeper.
Ena's suspicions were aroused when Martha bought a tin of best salmon from the corner shop and invited both her and Minnie Caldwell (Margot Bryant) to tea, even though it wasn't a Sunday.
It was during a singsong at a party in the Rovers thrown by Frank Barlow to celebrate his selling his shop that Martha became ill and retreated to her usual chair in the empty snug.
Helping Lily clear out the house, Ena and Minnie happened upon the record Martha and an unnamed man had made in Blackpool in 1934.
Although unable to identify the man in the recording, they realised that Martha had had an affair with him and were pleased to know that their friend had once had some fun in her life before returning to her violent husband.
January that year had seen Coronation Street beaten to first place in the ratings by a regular episode of another TV programme for the first time since November 1961 (the sitcom Steptoe and Son on BBC One).
Carol was the first to depart, with Martha suffering a fatal heart attack in the Rovers snug in Tim Aspinall's inaugural episode as producer, broadcast on 13 May 1964.
Due to the nature of the character's exit, and her popularity with the cast and viewers, Carol's colleagues fought her sacking, with Violet Carson threatening to resign.
When rehearsing the death scene, Peter Adamson refused to deliver the line "she's dead", and during recording he hesitated before saying it so that his words could be cut, with the order likely to come from Cecil Bernstein, one of Granada's chairmen who was the programme's strongest advocate within senior management.
After her sacking was announced by the press on 7 April, Carol spoke to a reporter, where she was resigned to her fate: "They've been three wonderful years, and I am sorry to be leaving so many good friends behind me."
By killing an established character he doubtlessly gave us a few episodes of high drama and created a talking-point in the factories and laundrettes which boosted our viewing figures for a period, but when the dust settled we were simply left with a Coronation Street without Martha Longhurst.