Helen McCrory, the Peaky Blinders actor who died from cancer on Friday, “swore friends to secrecy” as she underwent treatment, her friend Carrie Cracknell has revealed. Cracknell, who directed McCrory in a 2014 production of Medea, said the performer did not want her illness overshadowing her family and professional life. McCrory’s husband, Damian Lewis, announced the news that his wife died peacefully at home aged 52. Cracknell said the actor informed “very, very few people” about her diagnosis and continued with her charity work weeks before her death. The director told BBC’s Today programme: “Helen wanted to be very private about her illness and I understand why. When you live in the public spotlight you have to find space to protect the things that are just for you. “Very, very few people knew, and I only did because we were planning to transfer a show to Broadway and we had to cancel that because she was undergoing treatment. We were sworn to secrecy. “Her need to be fully alive and be committed and to take things incredibly seriously, such as her family and charity work, defined her last few years for her as much as ever.” Cracknell added that McCrory faced up to cancer “with a level of bravery and humour that was completely extraordinary”. “It was a very remarkable thing.” McCrory, who was awarded an OBE for services to drama in 2017, was best-known for playing fearsome matriarch Polly in Peaky Blinders as well as appearing in the Harry Potter franchise and The Special Relationship. Her last two appearances at the National Theatre were as Medea, in a play based on Euripides’ Greek tragedy, and as Hester Collyer in a revival of Terence Rattigan’s 1952 modern classic, The Deep Blue Sea. One of her final screen performances was as a barrister in last year’s ITV drama Quiz, based on the scandal surrounding Charles Ingram and his wife, Diana, who were accused of conspiring to steal the jackpot in Who Wants to Be a Millionaire? through a code based on coughing. Her husband, Lewis, a fellow actor, announced McCrory’s death on Twitter. He wrote: “I’m heartbroken to announce that after an heroic battle with cancer, the beautiful and mighty woman that is Helen McCrory has died … surrounded by a wave of love from friends and family.” Lewis added: “[Helen] died as she lived. Fearlessly. God we love her and know how lucky we are to have had her in our lives. “She blazed so brightly. Go now Little One, into the air, and thank you.”