Blaeu's decorative, and intriguingly off-centred, map of the North Polar regions, including Arctic North America, Scandinavia and northern Asia. The map is based on the discoveries of Baffin, Barentsz, Davis, Frobisher, Hall, James, and other, especially James' 1631-1632 voyage in Hudson's Bay. As with much Dutch cartography, the map promotes the existence of a north-east passage over that of a north-west. The map was originally published in 1640, but revised in 1645, as here, to inlude the coat of arms of the dedicatee, Gulielmo Backer.