Gu Yanwu (traditional Chinese: 顧炎武; simplified Chinese: 顾炎武; pinyin: Gù Yánwǔ; Wade–Giles: Ku Yen-wu) (July 15, 1613– February 15, 1682), also known as Gu Tinglin (Chinese: 顧亭林), was a Chinese philologist and geographer. He spent his youth during the Manchu conquest of China in anti-Manchu activities after the Ming Dynasty had been overthrown. He never served the Qing Dynasty. Instead, he traveled throughout the country and devoted himself to studies.