The house flag of the Koninklijke Nederlandsche Stoomboot Maats, Amsterdam. A rectangular blue flag with a white diamond in the centre bearing a gold crown. the flag is cotton, machine sewn and has a printed design. A rope is attached.

Koninklijke Nederlandsche Stoomboot Maats (KNSM) was founded in 1856 by Christian Ramann, a German, and two Dutch merchants: C.A. von Hemert and M.S. Insinger. The company began trading between Amsterdam and Baltic ports such as St. Petersburg and Copenhagen, as well as ports in France. By 1863 the company operated 11 ships. For a short period beginning in 1881, the company began regular routes to New York; however an agreement with Holland America Line in 1883 ended their North Atlantic sailings. In 1913, KNSM took control of Koninklijke West-Indische Maildienst (KWIM), another Dutch company which delivered mail to and from the Dutch West Indies. During World War I, although the Dutch were neutral, the Allies used Dutch fleets, including KNSM’s, to support their war effort. The company again suffered losses in World War II, losing four passenger vessels and 37 cargo ships. Post-war, KNSM re-established their trading routes, most notably to Central and South America. However, the decline in the shipping business in the 1970’s caused severe problems for the company and in 1981 it was purchased by the Royal Nedlloyd Group. In 2005 the Royal Nedlloyd Group was purchased by the shipping giant Maersk. This is currently the largest shipping company in the world, operating with an 18% share of the business worldwide.