The original title of the 'The Flowers of War' is '13 Flowers of Nanjing' (Chinese title: 金陵十三钗 - Jīnlíng Shísān Chāi). It is written by famous Chinese author Geling Yan (严歌苓).

The book tells a true story that took place during the 1937 Nanjing Massacre. Nanjing was the capital city of China in 1930s. On 13/12/1937, Japanese army invaded the city and slaughtered thousands Chinese soliders and civilians. This event is recorded in the school history books in China, so its a page of history every Chinese knows. Read more about Nanjing Massacre here.