_Dankelman_ the then Prime Minister, who cou’d not foresee the Situation that _Europe_ was in some Years after, would fain have diverted the Elector from a Project which he thought a perfect Chimæra; he put him in mind of the Difficulties _Frederic-William_ met with in it, and of the Reasons he had to refuse the Offers which _France_ made to him on that head; he shew’d him that the same Reasons were still subsisting, and reinforc’d by yet greater Difficulties; and that it was Madness to attempt a Thing, the Success whereof was neither certain nor advantageous, his Rank being so near a-kin to Royalty, that he would be never the better for the Title. But the Elector had the refusal of the Arm-chair too much at heart to hearken to any Reasons that could be brought against his Design, and sent _Dankelman_, his Minister’s Brother, to _Vienna_, to impart to the Emperor the Scheme which he had form’d to erect _Prussia_ into a Kingdom. _Prussia_, which is a Province detach’d from _Poland_, formerly belong’d to the _Lithuanians_, from whom it was conquer’d by the _Teutonic_ Order. _Albert_ Margrave of _Brandenburg_, the Grand Master of the said Order, who had marry’d _Dorothy_, Daughter of _Frederic_ I. King of _Denmark_, took it from those Knights in 1511, and made himself Master of it. This engag’d him in a War with _Sigismond_ I. King of _Poland_, his Uncle by the Mother’s side, who had Pretensions upon the said Province; which War continu’d five Years, till it was concluded by a Treaty, whereby it was stipulated, That the Eastern _Prussia_ shou’d remain hereditary with the Title of a Duchy to _Albert_, who, together with his Descendants shou’d perform Allegiance and Homage for it to the King and Republic of _Poland_, to which it was to revert on the failure of Issue Male in the Family of _Albert_. The Emperor _Charles_ V. oppos’d this Transaction, by pretending that _Prussia_ was a Fief of the Empire; and that therefore _Sigismond_ had no Right to dispose of it. The Imperial Decree which was pass’d upon this Occasion, had however no Effect, by reason of the Wars which the Emperor was at that time engag’d in, and _Albert_ remain’d in peaceable Possession of _Prussia_. He was succeeded by his only Son _Albert-Frederic_, who receiv’d the Investiture of it from the King of _Poland_, for himself and his Cousin-Germans in 1569. This Prince dying without Issue, _John Sigismond_ Elector of _Brandenburg_ succeeded him, and again receiv’d the Investiture of it from the King of _Poland_, for himself and his three Brothers. Since that time the Duchy of _Prussia_ has always been in the _Brandenburg_ Family from Father to Son; but the Elector _Frederic-William_ the Great, having made War upon _Charles-Gustavus_ King of _Sweden_, in favour of the Crown and Republic of _Poland_, the Sovereignty of _Prussia_ was, in Acknowledgment thereof, yielded to him, for himself and all his Male Descendants, by the Treaty of _Bydgost_ in 1659.