They fought on opposite sides during the War of the Austrian Succession (1740 – 1748), but the war saw both grow in power. Russia defeated Sweden and Prussia defeated Austria. Russia and Prussia again were at odds during the Seven Years' War (1756–1763) and fought the battles of Gross-Jägersdorf, Zorndorf, Kay and Kunersdorf. However, when Russian Tsar Peter III came to power, he made peace with Prussia by signing the Treaty of Saint Petersburg, allowing Prussian King Frederick the Great to concentrate on his other enemies.