During the early 18th century, Sweden was embroiled in the Great Northern War (1700–1721), a conflict that coincided with a devastating outbreak of the plague, affecting much of the Baltic region. This epidemic, part of a wider pandemic, reached Sweden through military and trade routes, exacerbating the already severe toll of the war. The plague arrived in Stockholm in June 1710, likely from a ship originating in Estonia or Livonia, both of which had already been ravaged by the disease during the war. Over 22,000 of Stockholm’s 55,000 inhabitants died, with women and children being particularly affected. From there, the plague spread to other regions of Sweden and Finland, killing large numbers in cities such as Uppsala and Helsingfors (Helsinki).
The devastation of the plague, which killed as much as two-thirds of the population in some Finnish towns, occurred during one of Sweden’s most challenging periods, as it faced military losses against Russia. The combination of war, plague, and famine weakened Sweden, hastening its decline as a major European power. Following the war, Sweden was forced to cede Estonia, Livonia, and parts of Finland to Russia in the Treaty of Nystad in 1721, solidifying Russia’s dominance in the Baltic and marking the end of Sweden's era of great power status.