Waves of Chinese emigration have happened throughout history. They include the emigration to Southeast Asia beginning from the 10th century during the Tang dynasty, to the Americas during the 19th century, particularly during the California gold rush in the mid-1800s; general emigration initially around the early to mid 20th century which was mainly caused by corruption, starvation, and war due to the Warlord Era, the Second Sino-Japanese War and the Chinese Civil War; and finally elective emigration to various countries. Most emigrants were peasants and manual labourers, although there were also educated individuals who brought their various expertises to their new destinations. 210 BCE: Qin Shi Huang (Chinese: 秦始皇) dispatched Xu Fu () to sail overseas in search of elixirs of immortality, accompanied by 3,000 virgin boys and girls. Records suggest Xu Fu's expedition settled in Honshu, Japan. From the Han dynasty onwards, Chinese military and agricultural colonies () were established at various times in the Western Regions, which in the early periods were lands largely occupied by an Indo-European people called the Tocharians. 661 CE: under the Tang dynasty, Zheng Guo Xi of Nan An, Fujian was buried at a Philippine island. Many Chinese merchants chose to settle down in the Southeast Asian ports such as Champa, Cambodia, Java, and Sumatra, and married the native women. Their children carried on trade. Borneo: Many Chinese lived in Borneo as recorded by Zheng He. Cambodia: Envoy of Yuan dynasty, Zhou Daguan () recorded in his The Customs of Chenla (), that there were many Chinese, especially sailors, who lived there. Many intermarried with the local women. Champa: the Daoyi Zhilüe documents Chinese merchants who went to Cham ports in Champa, married Cham women, to whom they regularly returned to after trading voyages. A Chinese merchant from Quanzhou, Wang Yuanmao, traded extensively with Champa, and married a Cham princess. Han Chinese settlers came during the Malacca Sultanate in the early 15th century.