1. It's based on a true story
Sally Wainwright, the head writer of Last Tango in Halifax, based the story of Celia and Alan's romance on her mother's experiences. Dorothy, Sally's mother, lost touch with a childhood sweetheart at the age of 15, but found him again 60 years later on Friends Reunited. Sally was inspired by how Dorothy "became so passionate and emotional" after reconnecting with her lost love, and that's where the inspiration for Celia's rediscovered romance comes from. Even certain scenes are lifted from real life events - remember when Celia and Alan laughed at Caroline's argument with her husband? That's based on an actual argument Sally had with her partner while her mother and stepfather giggled from the next room.
2. The show's original name was Antony & Cleopatra
The drama was originally called Antony and Cleopatra, named after the Shakespearean tragedy about two lovers who can't live without each other. Could the working title have foreshadowed a potentially tragic ending to Alan and Celia's relationship, or was it a reference to star-crossed lovers Caroline and Kate? Either way, Last Tango in Halifax is a better fit; it captures all the romance without the darker implications of Anthony & Cleopatra, and it has a proud reference to the show's Yorkshire setting.
3. Anne Reid and Sarah Lancashire go way back
On-screen mother and daughter pair Anne and Sarah have been friends for years; Sarah says "I've known Annie since I was a little girl." The Reids were friends of Sarah's parents when she was growing up, and Sarah describes working with Anne as "heaven". You can tell from their chemistry - even in the very first scene, when Caroline and Celia squabble over lunch, there's a sense of familiarity that is rarely seen in television pilot episodes.
4. Sally Wainwright intended to create flawed characters
Sally says that "when you invent characters, you've got to invent them warts and all," and the flaws she's given the Last Tango in Halifax family make them all more human. Rupert Graves, who plays Gary, admires "the latitude she gives to human error". This is clear from the characters' weaknesses. Despite Celia's warmth, she is undeniably intolerant - this is obvious when she refuses to go to her daughter's wedding. Caroline is also flawed, and she can be just as self-centred as she is brave. Even Kate calls her out on being a terrible listener at the beginning of their relationship. These realistic imperfections make the characters all the more believable and easy to relate to.
5. Sarah Lancashire has been flooded with fan mail
Sarah says that she has received the most fan mail she's ever had in her career for her role as Caroline due to Last Tango in Halifax's handling of the character's same sex relationship. It's not difficult to see how Sarah's performance inspires her fans, particularly in the scene in which Caroline calls out Michael for homophobia and blackmail. Her relationship with Kate is as central to the story as Alan and Celia's, and watching Caroline grow past her initial fear and self-consciousness to eventually be in an open, happy relationship with Kate is one of the most moving arcs of the show.
6. You can see the characters' birthdays in the opening credits
Ever noticed the tiny, almost illegible writing beneath the actors' names in the opening title sequence? Look extremely closely, and you'll be able to see each character's date of birth. The opening credits were cleverly created in the style of an authentic family tree, right down to the tiny details. Like the story, the opening titles start with Anne and Celia, and unfold to reveal details of all the people in their lives. See if you can make the dates out next time you watch.
7. Its depiction of the elderly has been praised
Even though Alan has heart problems, the protagonists never let their age stop them from living full lives, and the adorable awkwardness of Alan and Celia's first date is exactly the same as it would be for a young couple. When Alan says that "life is for living", he really means it, and this attitude makes the older characters anything but stereotypical or irrelevant. Lucy Harmer, an executive at Age UK, has openly endorsed Last Tango in Halifax's depiction of older people, saying "older characters are often vulnerable and frail; here we have two real, rounded individuals".