Because of his brilliant leadership of the Protestant forces in the Thirty
Years' War, became known as the Lion of the North.
When he succeeded to the throne in 1611, Sweden was at war with Denmark,
Russia, and Poland. Gustav concluded a peace with Denmark in 1613, but
Sweden regained its southern provinces only after agreeing to pay heavy
financial indemnities. He waged a successful war against Russia (1613-17),
acquiring lands that completely cut off Russian access to the Baltic Sea.
From 1621 to 1629, Gustav waged a war against his cousin, Sigismund III,
king of Poland, who maintained a claim to the Swedish throne. Poland was
forced to cede lands and cities along the southern and eastern Baltic
coasts in 1629, and Gustav's right to the Swedish throne was ensured. A
religious interest in the Protestant cause and a belief that conquest of
northern Germany by the Holy Roman Empire would be militarily and
economically dangerous to Sweden impelled Gustav to enter the Thirty
Years' War. After securing an alliance with France, he landed his army on
the coast of Pomerania and succeeded in driving the imperial forces back
from the Baltic. His victory at the Battle of Breitenfeld in 1631 gave the
Protestants the military advantage, and they went on to occupy Bavaria and
Bohemia. Gustav turned his army north in 1632. At the Battle of Lützen in
Saxony, he defeated the imperial forces, but was himself fatally wounded.
Gustav was noted not only as a great general but as a capable
administrator. With the help of his chancellor, Count Axel Oxenstierna,
who managed internal affairs and diplomacy while the king was involved in
military campaigns, Gustav developed a sound and centralized system of
government and did much to develop the natural mineral resources of his
country. He was succeeded by his daughter, Christina.