Had the wedding between Jasper Waller-Bridge – brother of Phoebe – and Michelle Dockery taken place in the Fleabag universe, the homily would include some kind of sexual innuendo, a guest would be caught naked in the vestry, the dress would be badly stained, and either the bride or groom would be consumed by anguished second thoughts.

But this was real life, and so on Saturday the sun shone on a picture-perfect Chiswick church, Dockery wore unblemished Emilia Wickstead and Phoebe Waller-Bridge looked every inch the star she is in a pink Etro suit while on the arm of her award-winning director boyfriend Martin McDonagh – the man behind hit films like In Bruges and The Banshees of Inisherin.

Although both the bride and the pink suit were nearly upstaged by the third finger of Phoebe’s left hand, which gleamed with what looked like an engagement ring. If she and McDonagh do marry, it will be not only a union between Britain’s best-loved screenwriter-directors, but the merging of two creative dynasties.

Now a global household name co-writing James Bond films and raking in millions thanks to her Amazon contract, it feels almost ironic that Phoebe, 38, stormed into the national consciousness by being as subversive as possible. Within the first two episodes of Fleabag, which was released on the BBC in 2016, we had already watched her have anal sex and masturbate to videos of Barack Obama.

The entire show prickled with outrageous humour, female vulnerability and sexual electricity – and by making its creator a star, it paved the way for an entire Waller-Bridge empire.

Not that the family were exactly nobodies to start off with. Landed gentry on both sides, the Waller-Bridge lineage boasts BBC news presenters, baronets, published authors and Conservative MPs.

Phoebe has nonetheless described her upbringing as middle class, and she and her older sister Isobel and younger brother Jasper grew up in a big house in leafy Ealing (a bike ride away from the church where this weekend’s wedding took place). Phoebe went to St Augustine’s Priory, a west London private school, before studying at Rada.

Drama school wasn’t an ideal fit. “I don’t think anyone thought much of me,” she said in an interview with Vanity Fair. “The classes seemed to focus on perfecting your voice and movements – the whole Laurence Olivier bit about projecting the words clearly and to the back of the hall. I just got really scared of getting it wrong. I’d always thought that the whole point was to kind of get it so wrong that it ends up being original.”

Of course, she was right, but someone who was friends with her at that time agrees that in a Rada intake that included Andrea Riseborough, Gemma Arterton and Gugu Mbatha-Raw, nobody expected Phoebe to emerge as the biggest star of all. “She was lovely and very popular but she wasn’t given much attention by staff – although it never seemed to bother her much.”

It was at Rada that Phoebe met Sian Clifford, who would go on to star as her sister in Fleabag, and in the years after she graduated, Phoebe became very close to actor-producer Vicky Jones, with whom she would found the DryWrite Theatre Company and collaborate on Fleabag. From there, she would meet acclaimed director Emerald Fennell and together they would create Killing Eve.

As Phoebe’s career took off, her brother and sister would, by dint of their distinctive last names, get caught up in her wake. In 2019, Phoebe expressed regret for this, saying that they and her parents – businessman Michael and livery clerk Teresa – have “taken the brunt” of the negative impact of her sudden fame.

Not that having such a well-connected sister can have harmed their careers. Isobel, 39, won a scholarship to the Royal Academy of Music, but got her big break when she wrote the score for Fleabag; in the years after it came out, she would score feature films Vita and Virginia, Emma and Netflix’s Munich: The Edge of War.

Isobel is now highly regarded – she performs regularly and has written music for the Philharmonic Orchestra and the Alexander McQueen show in Paris, and collaborated on a film with ballet dancer and actress Francesca Hayward.

Then there is brother Jasper, who at 35 is six years younger than his now-wife Michelle Dockery – a woman he was reportedly introduced to in 2019 by Phoebe. He too is in the industry, having worked as a television and film producer for over a decade, and founded a music production company called Day One Pictures. From 2017 to 2018, he was Louis Tomlinson’s manager.

Although Dockery’s side of the aisle may well have been the starrier one. Friendships formed over the course of six seasons of Downton Abbey meant many of Britain’s best-loved actors were in attendance at Saturday’s wedding: Lily James, Hugh Bonneville, Lesley Manville, Jim Carter and Imelda Staunton, as well as series favourites like Elizabeth McGovern and Laura Carmichael.

Some of the joy must have come from seeing Dockery grinning in a way Lady Mary would disapprove of – a happy turn of events given her tragic backstory. Dockery was previously engaged to public relations executive John Dineen, but he died from a rare form of cancer in 2015, aged just 34. Despite the fact they never had time to marry, she has previously described herself as a widow.

Now, Dockery is back in the fold of happy family life – not that she can lay claim to being the best connected in-law at the Waller-Bridge Sunday lunches. Ever since Phoebe ended her marriage to Irish television presenter and author Conor Woodman in 2017 and started dating Martin McDonagh, she became one half of Britain’s most successful screenwriting couple.

McDonagh is one of few men who wouldn’t be upstaged by the Fleabag-creator. He is an Oscar, Bafta and Golden Globe winner, and, like Phoebe, a former precocious genius. In his mid-20s, when he worked predominantly as a playwright, McDonagh was the first person since Shakespeare to have four plays staged simultaneously in London.

Over the years, he has attracted some controversy – once in London for refusing to toast the Queen at an industry event due to his Irish heritage, but also in Ireland, where critics have accused the British-born director of taking a misty-eyed and ultimately unrealistic view of the country of his parents’ birth. “We were brought up to be proud of being Irish, maybe more so than someone brought up in Dublin,” McDonagh has said, by way of explanation.

Like Phoebe, he has spent almost his entire life in London. Born in 1970 in Camberwell, (Phoebe too prefers an older partner, and at 53, McDonagh is 15 years her senior) he grew up the son of a construction worker and housekeeper in less privileged circumstances than his girlfriend. But both he and his brother, John Michael McDonagh – who wrote and directed The Guard and Calvary – have been hugely successful. John Michael is married to film producer and editor Elizabeth Eves and the brothers remain very close.

Martin McDonagh has also been partnered before, in his case to live-in girlfriend, assistant director Malina DeCarlo, with whom he shared a dog.

The newly engaged couple reportedly now live together in his Shoreditch townhouse. If they were that way inclined, their dinner parties could be a who’s who of the acting world: Woody Harrelson is an old friend of Martin’s and the two have played chess together for years, while Brendan Gleeson has starred in films written by both McDonagh brothers, and is an old family friend.

Phoebe – who is widely known for having kept her irreverent, off-beat sense of humour despite her fame – has a wide circle of friends, including Sian Clifford, Emerald Fennell, Andrew Scott, Emilia Clarke, Tuppence Middleton, and the author and journalist Elizabeth Day, who is married to entrepreneur Justin Basini – a relative of the Waller-Bridges. At this year’s Oscars, she was spotted laughing uproariously at the bar with cool kids Paul Mescal and Jessie Buckley.

In fact, wherever you look, there is another titan of film, screen, page or stage lurking – and yet amid this whirlwind, the pair remain remarkably un-starry. When asked about Phoebe in his last interview, McDonagh replied, “No comment, but thumbs up on my love life, thanks for asking.”

She has been slightly more open. Talking about whether they read each other’s work, Phoebe has said, “We don’t really share anything beforehand”. Partly because criticism would be difficult but also because “I just really, really fancy him. So if you show someone something, and you fancy them, it can become this blur.”

She does admit to admiring Martin long before meeting him – and no doubt the feeling is mutual. “It’s really useful being with someone who I think is a genius, it just ups your game. I would always have wanted Martin McDonagh to think of my work as good, whether I was with him or not. I find out now, either way.”