In the first half of the 17th century, a plague claimed some 1.7 million victims in Italy, or about 14% of the population. In 1656, the plague killed about half of Naples' 300,000 inhabitants. More than 1.25 million deaths resulted from the extreme incidence of plague in 17th-century Spain. The plague of 1649 probably reduced the population of Seville by half. In 1709–13, a plague epidemic that followed the Great Northern War (1700–21, Sweden v. Russia and allies) killed about 100,000 in Sweden, and 300,000 in Prussia. The plague killed two-thirds of the inhabitants of Helsinki, and claimed a third of Stockholm's population. Europe's last major epidemic occurred in 1720 in Marseille.