The company was started by Bernard Lewis and his brothers in 1948 in London as a private corporation. Till date, River Island is a private firm owned by the Lewis family. In 1948, Bernard Lewis started the business by selling fruits and vegetables and later knitting wool from a site in the East End of London. His three brothers joined him and the company expanded by opening nine stores under the name Lewis Separates.
Within the next 20 years, the business grew, and the company had 70 stores in the United Kingdom, and it was decided a new identity was needed. The company was rebranded to Chelsea Girl, and the business became the first UK fashion boutique chain that used bold fashion imagery, intense colors and pops music to strengthen the brand. After two brothers left the company in 1979, Bernard, David and their families were left in charge of the firm, which eventually led to the formation of the Lewis Trust Group. The company launched Concept Man stores in 1982 which were later merged with Chelsea Girl to become River Island in 1988.