In 1500, the empire of Maximilian I was divided into ten Imperial Circles. The Lower Rhenish-Westphalian Circle included the Northwest, from the lower Rhine to the coast, and reached to the River Weser in the East. The County of Oldenburg also belonged to it. This map of the Westphalian Circle is from the Great Atlas by Joan Blaeu (1596-1673). The Dutch Blaeu dynasty of publishers and cartographers published numerous maps and atlases in the 17th century. Willem Janszoon Blaeu (1571-1638) studied Astronomy and Cartography with Tycho Brahe. In 1633, Blaeu became the official cartographer to the Dutch East India Company (VOC). His son Joan Blaeu continued to run the company successfully until, in 1672, a fire destroyed the workshop in Amsterdam – together with the precious copper plates.