HBO’s War Unveils Official Trailer Ahead of October Premiere

HBO has released the official trailer for War, its new legal drama starring Dominic West and Sienna Miller. The eight-episode series is set to premiere Thursday, October 1, at 9 p.m. ET/PT on HBO, with episodes also available to stream on HBO Max. New episodes will be released weekly on Thursdays.

The series drops viewers into London’s elite legal world, where two rival firms find themselves on opposite sides of a highly publicized divorce. As the case escalates, professional competition begins to collide with ambition, loyalty and personal relationships.

Two Rival Law Firms Go Head-to-Head

Created by George Kay, the writer behind Lupin and Hijack, War centers on two of London’s most powerful law firms: Cathcarts & Sons and Taylor & Byrne.

Their rivalry intensifies when they take on the divorce of British tech entrepreneur Morgan Henderson, played by Dominic West, and international film star Carla Duval, played by Sienna Miller.

The high-profile case becomes the defining legal battle of the first season, placing the two firms directly against each other as they fight to secure victory for their respective clients. HBO describes the series as an anthology legal drama, with its first season built around the Henderson-Duval divorce.

The conflict also draws ambitious young lawyer Jonathan “Johnny” Warren, played by Archie Renaux, deeper into the competition between the firms.

The Cast of War

At Taylor & Byrne, Phoebe Fox stars as Serena Byrne, while James McArdle plays Nicholas Taylor. The two are partners both professionally and personally.

Across the legal divide, Nina Sosanya plays Beatrice “Queen Bea” Ubosi, with Pip Torrens portraying St John Smallwood for Cathcarts & Sons.

The ensemble cast also includes Celia Imrie, Nick Mohammed, Emma Laird, Aran Murphy, Archie Panjabi, Adrian Scarborough, Shaheen Jafargholi, Akiya Henry, Honor Swinton Byrne, Miles Jupp, Kartanya Maynard, Alexandra Mardell, Dylan Edwards, Mark Quartley and Steve Furst.

George Kay Leads the Creative Team

Kay created and wrote War and serves as an executive producer on the series.

The show is co-produced by New Pictures and Observatory Pictures, in association with Sky and HBO. Executive producers include Willow Grylls and Matt Sandford for New Pictures, along with Susan Breen, Ben Taylor, Andrea Dewsbury and Megan Spanjian for Sky.

Ben Taylor serves as lead director, while Laurie Borg is the series producer.

HBO and Sky previously announced a two-series commitment for War. Sky has also confirmed that production on the second series is already underway.

War Premiere Date and Trailer

In the United States, War premieres October 1, 2026, at 9 p.m. ET/PT on HBO, with streaming available on HBO Max. The eight-episode first season will continue with new installments every Thursday.

The series will premiere in the UK on October 2 on Sky and NOW.

The official trailer gives viewers a closer look at the escalating battle between Cathcarts & Sons and Taylor & Byrne, as Morgan and Carla’s divorce turns into a major legal showdown.

Watch the Official Trailer

War premieres October 1 on HBO and HBO Max.