Prokofiev had been considering making an opera out of Leo Tolstoy's epic novel "War and Peace", when news of the German invasion of the Soviet Union on 22 June 1941 made the subject seem all the more timely. Prokofiev took two years to compose his original version of "War and Peace". Because of the war, he was evacuated together with a large number of other artists, initially to the Caucasus, where he composed his Second String Quartet. By now, his relationship with the 25-year-old writer and librettist Mira Mendelson (1915–1968) had finally led to his separation from his wife Lina. Despite their acrimonious separation, Prokofiev had tried to persuade Lina and their sons to accompany him as evacuees out of Moscow, but Lina opted to stay.