William Keswick, founder of the dynasty, was born on January 1, 1835 (some sources say 1834), in the
Scottish Lowlands. His grandmother, Margaret Jardine Johnstone was a sister of Dr.
William Jardine, the founder of Jardine's. His father Thomas Keswick, from Dumfriesshire had married Jardine's niece and entered the Jardine business. The company operated as merchant traders and had a major influence in the
opium wars although the company stopped this trading in 1870 to pursue a broad range of trades including shipping, railways, textiles and property development.
William arrived in China and
Hong Kong in 1855, the first of five generations of the Keswick family to be associated with Jardine's. He established a Jardine Matheson office in Yokohama, Japan in 1859. He returned to Hong Kong to become a partner of the firm in
1862. He left Hong Kong in
1886 to take control of
Matheson & Co. in
London.