Frederick William I (German: Friedrich Wilhelm I.; 14 August 1688 – 31 May 1740), known as the "Soldier King" (German: Soldatenkönig), was King in Prussia and Elector of Brandenburg from 1713 until his death in 1740, as well as Prince of Neuchâtel.
Frederick William II (German: Friedrich Wilhelm II.; 25 September 1744 – 16 November 1797) was King of Prussia from 1786 until his death in 1797. He was in personal union the Prince-elector of Brandenburg and (via the Orange-Nassau inheritance of his grandfather) sovereign prince of the Canton of Neuchâtel.
The union of Ducal Prussia with Brandenburg was fundamental to the rise of the Hohenzollern monarchy to the rank of a great power in Europe. John Sigismund’s grandson Frederick William of Brandenburg, the Great Elector (reigned 1640–88), obtained by military intervention in the Swedish-Polish War of 1655–60 and by diplomacy at the Peace of Oliva (1660) the ending of Poland’s suzerainty ...