Love stories are as old as the movies themselves. Older in fact. And yet, until fairly recently, love stories between people of the same sex have been depressingly rare—and rarer still in period pieces which often tend to remember history through a highly selective lens. Yet writer-director Francis Lee’s Ammonite joins a series of recent films that appear to challenge that, offering a sweeping historical romance in which lovers are women, played here by Kate Winslet and Saoirse Ronan.