While at Loevestein, Grotius maintained contact with the outside world via Maria, who was able to live with him but could also travel outside, and through correspondence with friends and relatives. He also kept on writing and the books he needed for his research were delivered in a large wooden chest. After two years of imprisonment, Grotius would escape Loevestein in this chest on 22 March 1619, in a daring plan devised by Maria.