After the success of invading Poland, Charles XII decided to make an attempt at invading Russia, but this ended in a decisive Russian victory at the Battle of Poltava in 1709. After a long march exposed to Cossack raids, the Russian Tsar Peter the Great's scorched-earth techniques and the extremely cold winter of 1709, the Swedes stood weakened with a shattered morale and were enormously outnumbered against the Russian army at Poltava. The defeat meant the beginning of the end for the Swedish Empire. In addition, the plague raging in East Central Europe devastated the Swedish dominions and reached Central Sweden in 1710. Returning to Sweden in 1715, Charles XII launched two campaigns against Norway on 1716 and 1718, respectively. During the second attempt, he was shot to death during the siege of Fredriksten fortress. The Swedes were not militarily defeated at Fredriksten, but the whole structure and organisation of the campaign fell apart with the king's death, and the army withdrew.