 Complete the following phrase:  The position of the Commonwealth with respect to the Duchy of Prussia kept getting weaker, as the power in the Duchy was being taken over by the Electors of Brandenburg. Under the electors, the Duchy had become ever more closely linked to Brandenburg, which was harmful to the political interests of the Commonwealth. Sigismung III left the Duchys administration in the hands of Joachim Frederick, and then John Sigismund, who in 1611 acquired the right to Hohenzollern succession in the Duchy by the consent of the King and the Sejm. He actually became the Duke of Prussia in 1618, after the death of Albert Frederick, and was followed by George William and then Frederick William, who in 1641 in Warsaw for the last time paid a 