The Treaty of Berlin was concluded on 2 May 1715, during the Great Northern War. It allied George I of Great Britain, as Elector of Hanover, with Denmark-Norway in turn for the cession of the Swedish dominion Bremen-Verden, which was occupied by Denmark, to Hanover. With the treaty, Denmark and Hanover joined the Russo-Prussian coalition established by the Treaty of Schwedt. Denmark was assured the gain of yet to be conquered Stralsund.
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Treaty of Berlin (1715) Wikipedia(Text) CC BY-SA