Passage: After the death of Elizabeth of Russia, czarina of Russia, her nephew Peter III came to the throne. Peter was a great admirer of Frederick the Great and all things Prussian, and Frederick used this to his advantage. Peter promptly withdrew his army from the war, abandoned Russian-occupied East Prussia, and signed a treaty of peace with Frederick. Peter then sent a force to aid the Prussian army in the campaign against the Austrians.

Question: Who ended up signing a treaty peace with Frederick after withdrawing his army from the war?
Peter