The marriage in War belongs to Morgan Henderson, a tech entrepreneur, and Carla Duval, an international film star, but the rivals in this HBO Max legal drama work for two London law firms. Actors Dominic West and Sienna Miller play the couple. Cathcarts & Sons and Taylor & Byrne take everything else. The series comes from George Kay, the writer who co-created Lupin and Hijack, and it is built as an anthology: the firms stay, the case changes each season, and the first case is a divorce.

The first episode’s synopsis sets the terms. The couple’s ten-year marriage is heading for divorce, and each side’s lawyers begin to ramp up their war rooms. The audience’s way into that world is a young lawyer, Jonathan “Johnny” Warren, played by Archie Renaux, who is drawn into what the official description calls “a ruthless world where ambition is currency, betrayal is strategy, and winning is everything.” The same description says the case “sends shockwaves through boardrooms, bedrooms, and courtrooms alike,” and the trailer sells it as “the biggest divorce trial in British legal history.”

One sentence, said to both sides

The line the promotional campaign keeps returning to is a short one: “You are the wronged party here.” Both Morgan and Carla hear it. On paper, that sentence is the engine of the show. A divorce drama usually asks who ended the marriage. War’s premise asks something colder: what happens when two firms are each paid to convince their client of the answer, and then to prove it in court. The setup produces two versions of the same ten years, drafted by opposing counsel, and a trial that can only accept one of them.

That is a writer’s premise before it is a legal one. Kay’s best-known television runs on a fixed frame that he then puts under pressure. Criminal, the Netflix anthology he created with Jim Field Smith, kept the same police interview room and changed the suspect each episode. Hijack held its story to the length of a single flight. War moves that logic from the episode to the season. The firms are the set and the resident company; each season hands them a new brief. Read that way, West and Miller are less the heart of a two-hander than guest leads arriving at a house with its own long-running cast.

The firms are the real ensemble

The supporting roster is built around the lawyers. Phoebe Fox plays Serena Byrne and James McArdle plays Nicholas Taylor, characters who share their surnames with Taylor & Byrne. Nina Sosanya plays Beatrice Ubosi, known as “Queen Bea”, and Pip Torrens plays St John Smallwood. Celia Imrie, Nick Mohammed, Emma Laird, Archie Panjabi, Adrian Scarborough and Miles Jupp complete a company long enough to suggest that the partners, juniors and rivals inside each building matter as much as the couple who hired them.

That weighting is what separates War from the British legal dramas it will be measured against. Silk, the BBC series, followed barristers competing for promotion inside one set of chambers. The Split, also for the BBC, followed a family of London divorce lawyers. Both kept the lawyers at the centre, but they worked through a new case almost every week. War’s pitch is narrower and longer: two institutions fighting over a single client file for a whole season, with every junior’s career riding on the result.

Why London, and why a divorce

The setting is not decoration. British newspapers have long called London the divorce capital of the world, because English courts, since the House of Lords ruling in White v White in 2000, start from a yardstick of equal division of a couple’s assets. That principle has drawn wealthy international couples to file in London rather than elsewhere, and it turned the city’s family-law practices into a business with famous clients and front-page cases of its own. A split between a tech founder and a film star, fought by two elite firms, is a fictional case placed inside a very real market.

The casting carries its own echoes. West played Prince Charles in the final two seasons of The Crown, through the years when the royal marriage came apart in public. Miller played a wife watching her husband stand trial in Netflix’s Anatomy of a Scandal. Neither credit has anything to do with War’s story. Both actors, though, arrive with an audience that has already watched them inside a public marriage going wrong, which is exactly the kind of case these fictional firms exist to take.

A second case is already in production

HBO and Sky have treated War as a franchise from the start. The two companies ordered two seasons together, and the second is already in production with a new case and a new cast: Marisa Tomei, Kelly Macdonald and David Harewood lead a defamation story, with Richard Schiff also cast. The firms come back; the clients do not. That structure is the real bet. If it holds, audiences will follow a law firm from one scandal to the next the way they have long followed a hospital or a police station.

Which leaves the question the campaign’s repeated line cannot settle. When each side of a ten-year marriage has been told by its own lawyers that it is the injured party, and each firm is paid to make that true before a judge, somebody still has to decide what actually happened inside the marriage. War’s premise gives that job to the lawyers. Whether anyone in either building is paid to find out is the question the series leaves on the table.

War: cast, episodes and where to watch

Is War based on a true story? No. No real case has been named as its source: the series is an original drama written by George Kay, and the Henderson–Duval divorce is fictional.

Who is in the cast? Dominic West (Morgan Henderson), Sienna Miller (Carla Duval), Archie Renaux (Johnny Warren), Phoebe Fox (Serena Byrne), James McArdle (Nicholas Taylor), Nina Sosanya (Beatrice Ubosi) and Pip Torrens (St John Smallwood). Ben Taylor is the lead director, with episodes also directed by China Moo-Young and Jennifer Sheridan.

How many episodes does War have? The first season has eight episodes, released weekly.

Where can I watch War? In the United States on HBO and HBO Max. HBO Max also carries it in Australia, Southeast Asia, Latin America, France and Belgium. In the UK and Ireland it is a Sky Original on Sky Atlantic and NOW; Sky also carries it in Italy, and Sky and WOW in Germany, Austria and Switzerland.

Will there be a season 2? Yes. It was ordered alongside the first and follows a defamation case with Marisa Tomei, Kelly Macdonald and David Harewood.

War premieres on HBO on Thursday, October 1, 2026, at 9 p.m. ET, streaming on HBO Max the same night, with new episodes weekly through November 19. Sky launches the series in the UK on October 2. It was filmed from September 2025 at OMA X Film Studios in Enfield, north London, and is produced by New Pictures and Observatory Pictures with Sky and HBO; Laurie Borg is the series producer.