Van Os was born in
Antwerp to a trader in
pigments and
tapestries, originally from
's-Hertogenbosch, who had moved to Antwerp around 1550. Dirck served as captain of militia in the
Fall of Antwerp, wherein the city surrendered to the
Duke of Parma. After this point he moved to
Middelburg. In January 1588, Van Os married Margretha van de Piet. He and his brother Hendrick traded in leather, grain and precious stones, primarily in the
Levant and cities on the
Baltic Sea. In 1595, he organized an expedition with
Isaac le Maire to get salt in
Setúbal and ship it to
Arkhangelsk. In 1602 he was one of the founders of the
Dutch East India Company, and served as one of the first directors. (The brothers hired a bookkeeper who moved in.) With 47,000 guilders, they were the largest investors. This number grew to 120,000 by 1609. The oldest
stock share in the world, dated 27 September 1606, was also signed by him. The company had an account at the
Wisselbank from the beginning. At that time they were involved in the expedition of
Henry Hudson to find an alternative route to the East. In 1612 Van Os acquired more than one-seventh of the land in
Beemster and in the
Purmer His portrait is in the
Stedelijk Museum Alkmaar. ==Family==