With ancestors from
Jiangxi province, Xu Xiake was born in what is today
Jiangyin (in
Jiangsu province) as Xu Hongzu (), as the second son of Xu Yu'an (徐豫庵, 1545–1594) and Wang Ruren (王孺人, 1545–1625). It was often said his mother encouraged him to travel and this shaped Xu's predilections. His sobriquet is Zhenzhi ().
Xiake was an alternate
sobriquet () given to him by his friend
Chen Jiru (陳繼儒, 1558–1639) and it means "one who is in the sunset clouds". His other friend,
Huang Daozhou (黃道周, 1585–1646), also gave Xu an alternate sobriquet:
Xiayi (), meaning "untrammelled in the sunset clouds." On his journeys throughout China, he travelled with a servant called Gu Xing (). He faced many hardships along the way, as he was often dependent on the patronage of local scholars who would help him after he had been robbed of all his belongings. Local Buddhist abbots of the various places he visited often would pay him money as well, for the small service of recording the history of their local monastery. From the snowy passes of
Sichuan, to the subtropical jungles of
Guangxi and
Yunnan, to the mountains of
Tibet, Xu Xiake wrote of all his experiences and provided enormous amounts of written detail from his observations. ==Travel records==