The portion of the country bordering on the North Sea, called Frisia, was situated within the provinces of North Holland, Friesland and Groningen, and in Germany to the River Ems. The people were known for their care and breeding of cattle. The Frisii, preferring pastoral pursuits to warfare, paid a tax of ox hides and ox horns to the Roman government, whereas the Batavii furnished soldiers and officers to the Roman army; these fought successfully in the various Roman wars. The Frisii bred the same strain of cattle unadulterated for 2,000 years, except from accidental circumstances. In 1282 CE, floods produced the Zuiderzee, a formed body of water that had the effect of separating the cattle breeders of the modern day Frisians into two groups. The western group occupied West Friesland, now part of North Holland; the eastern occupied the present provinces of Friesland and Groningen, also in the Netherlands.