Vanessa Redgrave was originally cast as Queen Elizabeth but was replaced by Glenda Jackson. She was later re-cast as the title character. Redgrave later played Queen Elizabeth in Anonymous (2011).
The film was released the same year as the mini-series Elizabeth R (1971), in which Glenda Jackson played Queen Elizabeth I. In that production, Vanessa Redgrave's mother Rachel Kempson played Kat Ashley, Queen Elizabeth's governess during her childhood and the Lady of the Bedchamber during the early part of her reign.
It took all day to set up the hunting scene, with Glenda Jackson in costume the entire time, as dog handlers and hawk handlers rehearsed their cues. The cameras finally rolled late in the afternoon, with the light beginning to fade and drizzle falling. The shot was perfect; everyone moved on cue. Unfortunately, one dog handler in a bright green shiny plastic raincoat released her hound, but forgot to stop where she was. She ran into the shot, ruining the take and wasting the entire day's shooting.
Jane Fonda, Mia Farrow, and Sophia Loren were the first choices to play Mary. Vanessa Redgrave was the fourth choice. Dame Maggie Smith was in talks, but plans fell through.
According to a 1974 interview, the role of Mary was intended for Geneviève Bujold. She turned it down after refusing to be typecast in movies about doomed sixteenth century Queens, leading to a major fallout with producer Hal B. Wallis. Oddly enough, her replacement, Vanessa Redgrave, had appeared in A Man for All Seasons (1966) as Anne Boleyn, the same role Bujold had played in Anne of the Thousand Days (1969).
Vanessa Redgrave had to learn the title song "Vivre et Mourir" phonetically, because she could not speak French.
Vanessa Redgrave was in her early thirties during filming. For most of the movie, Mary is in her teens and twenties.
Vanessa Redgrave (Mary, Queen of Scots) and Timothy Dalton (Lord Darnley) later played another married couple, Agatha Christie and Colonel Archibald Christie, in Agatha (1979). Although they never married in real life, they were in a relationship from 1971 to 1986.
In the scene introducing Elizabeth and Robert Dudley, he is singing a song he says was composed by Henry VIII for her mother, Anne Boleyn. When Elizabeth asks how her mother liked it, Dudley says that Anne replied by asking Henry how his wife (Catherine of Aragon) liked it. In Anne of the Thousand Days (1969), which was also directed by Charles Jarrott, this same song is performed at a banquet by Henry VIII (Richard Burton), who asks Anne Boelyn (Geneviève Bujold) how she likes the song. Anne replies "How does your wife like it?"
Gone with the Wind (1939) producer David O. Selznick owned the rights for many years. Veteran director Alexander Mackendrick had been trying to set it up for many years. In April 1969, he was finally set to go, with Mia Farrow starring, a James Kennaway script, and sets built at Pinewood, when Universal, burdened by heavy losses, cancelled all of its European productions.
Closing credits epilogue: Elizabeth ruled England for another sixteen years. She died as she had lived, unmarried and childless. The Throne of England and Scotland passed to the only possible claimant, a man, King James the First, only son of Mary Stuart, Queen of Scots.
When Alexander Mackendrick was set to direct, Oliver Reed was to play James Stuart.