Trailer for HBO's WAR Pits Sienna Miller and Dominic West Against Each Other in a Brutal Divorce Battle

HBO Max and Sky are turning a celebrity divorce into all-out legal combat with War, a spicy new legal thriller starring Sienna Miller and Dominic West.

The full trailer has arrived, and this divorce looks ready to leave plenty of collateral damage across London when the series premieres October 1st, 2026.

West stars as tech titan Morgan Henderson, while Miller plays his estranged wife, international film star Carla Duval. Their marriage may be finished, but the real fight is only beginning as their divorce puts two of London's most powerful law firms, Cathcarts & Sons and Taylor & Byrne, on opposing sides.

The case quickly spreads beyond the courtroom, shaking up boardrooms and bedrooms as money, secrets, careers, and reputations are thrown into the fight.

Young lawyer Jonathan "Johnny" Warren also gets pulled into the situation, finding himself in a ruthless corner of London's legal world where ambition is currency, betrayal is strategy, and winning is everything.

The trailer offers a taste of the dirty tactics and personal attacks coming from both sides without giving away too much. It looks like War is going to have plenty of sharp legal maneuvering mixed with the messier personal drama surrounding Henderson and Duval's crumbling marriage.

The series comes from George Kay, whose credits include Lupin, Hijack, Killing Eve, Criminal, Litvinenko, The Long Shadow, Gone, and Stag. Kay writes alongside Jess Brittain, Kelly Jones, Emilie Robson, Krissie Ducker, Yemi Oyefuwa, and Catherine Shepherd. China Moo-Young, Ben Taylor, and Jennifer Sheridan direct episodes.

Miller and West are joined by Archie Renaux, Marisa Tomei, Kelly Macdonald, David Harewood, Richard Schiff, Pip Torrens, Miles Jupp, Honor Swinton Byrne, and Phoebe Fox.

This divorce also won't be the end of the legal bloodshed. Season 2 is already filming and will bring Cathcarts & Sons and Taylor & Byrne back into conflict for an explosive defamation case that follows the events of the divorce.

New Pictures and Observatory Pictures produced War for Sky and HBO. The series will premiere simultaneously in the U.S. and UK, with HBO Max launching it on October 1st.