In a recent Guardian interview, the actress Harriet Walter reflected on the impossibility of ever really knowing another human being. Yet, like the novelist Hilary Mantel, she has devoted her professional life to inhabiting characters not her own, often historical ones. Walter’s notable roles include Elizabeth I, Lady Macbeth and Cleopatra, while Mantel has twice won the Man Booker Prize for her extraordinary portrayal of Thomas Cromwell in Wolf Hall and Bring Up the Bodies (all reviews here) – adapted for the stage by the RSC, currently playing in the West End, and soon to be serialised on BBC 2. In a conversation jointly hosted by the RSL and Intelligent Life magazine, and chaired by the playwright Timberlake Wertenbaker, they reflect on how they get to grips with a character, compare notes on capturing personality on the page and the stage, and discuss how to maintain a sense of self while becoming someone else.