Initially a staunch critic of the Kuomintang's nationalistic view of history, he grew more sympathetic towards it following the outbreak of the Second Sino-Japanese War and the university's evacuation to Chongqing.

Suzhou was a center of scholarship during the late Qing Dynasty; both his father and grandfather were prominent local academics, ultimately descended from the 17th century scholar-official Gu Yanwu.

[1][3] Gu was fascinated by historical texts such as the Zuo Zhuan, although his grandfather forbid him from reading them until he was first taught the Odes and the Book of Rites by a private tutor.

[5] After the imperial examination system was abolished in 1905, Gu entered private school, attending a class taught by his father at a residence north of Suzhou.

[5][6] In 1906, he transferred to a grammar school in Suzhou, which taught a mix of traditional and western-style material; disappointed in this modernized education, his grandfather continued giving him separate instruction in the Classics.

His grandfather died around this time, leaving Gu to pursue increasingly heterodox study material, taking particular inspiration from the work of Tan Sitong.

[12] After reading the work of 18th century historian Zhang Xuecheng the following year, Gu became dedicated to disproving the notion that a Golden Age occurred in ancient Chinese history.

[32] The success of the Folksong Weekly and a growing interest in other forms of folk culture among its members led to the formation of the Customs Survey Society on 14 May 1923.

[31] The publication of these letters resulted in a large amount of responses from both supporters and opponents of his views across various major journals and newspapers, pitting the emerging Doubting Antiquity School against more conservative historians.

Gu later compiled the responses to his article into the first volume of his Gushi Bian [zh] (古史辨; 'Debates on Ancient History'), which would ultimately become a seven-volume work published from 1926 to 1944.

He produced a major study on the legend of Lady Meng Jiang, editing together various folk songs, drawings, epigraphs, and Baojuan (mystical prosimetric texts) based on the story.

By the end of the year, fighting had broken out in the city between the forces of Feng Yuxiang and rival warlords Wu Peifu and Zhang Zuolin.

[38] Under the administration of university president Lim Boon Keng, Xiamen emerged as a center of cultural studies, recruiting many scholars displaced from Beida.

In a short story titled Li-shui ('Controlling the Waters'), Lu featured a stuttering caricature of Gu named Niaotou Xiansheng (鳥頭先生; 'Mister Birdshead'), making fun of both his physical appearance and lifelong speech disorder.

In a letter published in the Journal of Sun Yat-Sen University in January 1928, he dubbed Gu the "Newton and Darwin of ancient Chinese history" and the "king of historiography".

Titled Yugong Biweekly (after the Yu Gong, an ancient geography text within the Shujing), articles within the journal were generally written by Gu's graduate students and supervised by Tan as chief editor.

Due to its denial of an ancient Chinese golden age, the Kuomintang prevented Gu's textbook Elementary National History from being used in schools, and issued a large fine on the Commercial Press for its publication.

Writing to Fu Sinan to request government subsidies in October 1935, Gu emphasized the nationalistic origins of the journal, stating that its intention was to "inspire readers to take back our lost territory and to build up a solid basis for nationalism".

In the book, Gu heavily criticizes the Kuomintang's historiography, describing the concept of the Five Races[α] descended from the Yellow Emperor as historically incorrect and as a misguided lie for the sake of national unity.

[60] Under increasing political opposition from both left-wing and right-wing sources, Gu returned to Suzhou in July 1947, where he worked as a teacher and edited the periodical Minzhong Duwu (Chinese: 民眾讀物; lit.

He declared Hu his "personal and political enemy", although mainly recounted experiences at Beida, and reserved strong criticism to a small portion at the end of the statement.

[65] Gu worked alongside Rudolf Viatkin [ru], the vice-president of the Soviet Academy of Sciences, to assist in the production of a Russian translation of the Shiji.

His library (totaling over 70,000 volumes) was sealed off, leaving him to continue his studies on the Book of Documents based off the small amount of material which survived alongside his own memory of the classic.

In order to avoid the suppression of his research, he wrote using fountain pen in primary school copybooks he left on his children's desks; due to their stark contrast from his previous notebooks, Gu referred to them as his "special books".

[68] In 1971, Zhou Enlai ordered the Zhonghua Book Company to continue its stalled project to produce modern punctuated versions of the orthodox histories.

He recalled a large number of academics from the countryside and retirement to work on the project, including Gu alongside other noted historians such as Bai Shouyi, Wang Zhonghan [zh], Yang Bojun, and Zhang Zhenglang.

With his former students Liu Qiyu [zh] and Wang Xuhua serving as aides, he organized a large body of work into what would become posthumous publications.

[77] He wrote that prior to the formalization of these texts, the Hundred Schools of Thought during the Warring States period offered a relatively free and open scholarly discourse.

In a 1923 letter to Qian Xuantong, he theorized that the mythical founder of the Xia dynasty, Yu the Great, was a deified animal depicted on the Nine Tripod Cauldrons who was later reimagined as a human ruler.

He was strongly supportive of the incorporation of minority ethnic groups within the Chinese nation, although opposed historically to the concept of the Five Races descended from common mythic ancestors.