On the other bank of the Rhine next to the Batavi, in the modern Kennemer district (North Holland beyond Amsterdam), dwelt the Cannenefates, closely related to them but less numerous; they are not merely named among the tribes subjugated by Tiberius, but were also treated like the Batavi in the furnishing of soldiers. The Frisians, adjoining these further on, in the coast district that is still named after them, as far as the lower Ems, submitted to Drusus and obtained a position similar to that of the Batavi. There was imposed on them instead of tribute simply the delivery of a number of bullocks' hides for the wants of the army; on the other hand they had to furnish comparatively large numbers of men for the Roman service. They were the most faithful allies of Drusus as afterwards of Germanicus, useful to him in constructing canals as well as especially after the unfortunate North Sea expeditions (p. 53). They were followed on the east by the Chauci, a widely extended tribe of sailors and fishermen along the coast of the North Sea on both sides of the Weser, perhaps from the Ems to the Elbe; they were brought into subjection to the Romans by Drusus at the same time with the Frisians, but not, like these, without resistance. All these Germanic coast tribes submitted either by agreement or at any rate without any severe struggle to the new rule, and as they had taken no part in the rising of the Cherusci, they still continued after the battle of Varus in their earlier relations to the Roman empire; even from the more remote cantons of the Frisians and the Chauci the garrisons were not at that time withdrawn, and the latter still furnished a contingent to the campaigns of Germanicus. On the renewed evacuation of Germany in the year 17 the poor and distant land of the Chauci, difficult of protection, seems certainly to have been given up; at least there are no later evidences of the continuance of the Roman dominion there, and some decades later we find them independent. But all the land westward of the lower Ems remained with the empire, whose boundary thus included the modern Netherlands. The defence of this part of the imperial frontier against the Germans not belonging to the empire was left in the main to the subject maritime cantons themselves. [Sidenote: Limes and desert-frontier on the lower Rhine.]