At 1645 the Swedish Army sieged the city of Brno. The Swedes suffered heavy losses but never managed to seize Brno. The research question of the thesis is: “According to the Swedish doctrine of land operations, what fundamental military abilities were responsible for the outcome of the siege of Brno?”The research question will be answered conducting a case study of the Swedish siege of Brno derived from a qualitative study of literature. The result of the research conducted in the thesis concludes that the lack of the fundamental military ability command and control in the Swedish Army was the main reason why the Swedes were not able to size Brno and also to a lesser degree the lack of intelligence and information.