HBO is going to "War" this fall. The U.K. legal drama starring Dominic West and Sienna Miller will premiere Thursday, October 1 at 9 p.m. on HBO, TVLine has learned, and will be available to stream on HBO Max as well. Season 1 revolves around a bitter divorce between British tech entrepreneur Morgan Henderson and international film star Carla Duval, played by West and Miller. The cast also includes Phoebe Fox, James McArdle, Nina Sosanya, Pip Torrens, Celia Imrie, and Nick Mohammed. HBO has also released a teaser trailer for the series; press PLAY above to get a sneak peek.