The history of Sumitomo dates back to the early 17th century, when Masatomo Sumitomo (1585–1652) opened a book and medicine shop in Kyoto. Later in life, he created his Founder’s Precepts, which laid out his business principles. The Sumitomo Business Philosophy, stressing integrity and sound management, is based on Masatomo’s precepts and has been a central force shaping the spirit of each Sumitomo company for more than four centuries. Sumitomo’s initial core business was copper mining. It later diversified into a variety of fields, including finance, insurance, iron and steel, and real estate, and is now one of Japan’s representative business groups.