Romans invade, slogans loom large and Douglas Gordon wants everything – the week in art

Cavalry sports helmet in form of an Amazon showing as part of Legion at the British Museum. Photograph: ©The Trustees of the British Museum

Exhibition of the Week

Legion: Life in the Roman Army
A celebration of the all-conquering Roman army that made its mark on ancient history and has haunted the ages. But what was life as a legionary really like?
• British Museum, London, from 1 February to 23 June