Lennart Torstensson, Count of Ortala from 1646, took part in the Swedish campaign during the Thirty Years’ War. In 1641 he was appointed to lead the Swedish army, with which he succeeded in capturing Olomouc in June 1642. They damaged or completely destroyed many monuments, such as the Hradisko Monastery, and rebuilt the city.
In 1642, Torstensson led an attack from Saxony into Silesia, defeating the imperial army at Svídnice and Breitenfels and capturing Olomouc.
On 15 June 1642, five regiments of Torstensson’s army entered Olomouc. Olomouc became the most important stronghold of the Swedes in the Habsburg Monarchy. After the Swedes occupied the town, they began to rebuild it into a military fortress. They demolished Olomouc’s suburbs, set about repairing the city walls and demolished the nearby Hradisko Monastery. From the beginning of the Swedish occupation, the population left the town in droves, almost all the clergy left, and in violation of the terms of the surrender, Swedish soldiers were stationed not only in town houses, but also among the nobility and clergy.
In the spring of 1643, the Swedes were pushed out of many of the surrounding towns by the imperial army. However, the Swedish garrison remained in Olomouc due to war reparations until July 1650. The once thriving metropolis of Moravia remained depopulated and plundered after the Swedes left (valuable volumes of the libraries of the local monasteries were taken to Sweden). The Swedish occupation caused the greatest population and economic disaster in the history of the city.
Torstensson returned to Sweden in 1646, where he became governor of several provinces. He died in Stockholm in 1651.
