Except for some formerly insular areas, the region now called Zeelandic Flanders was not part of the historical County of Zeeland, but a part of the County of Flanders initially ruled by the House of Habsburg. The region was front line in the Eighty Years' War and was conquered by the Dutch Republic in 1604. As such, it was the only part of Flanders, which took part in the insurgency, to become part of the new republic.