Mieczysław Słaby was born on 9 December 1905 in Przemyśl. He graduated from the Medical Department of Jan Kazimierz University in Lwów in 1933. On 4 August 1939 he was sent to the Military Transit Depot on Westerplatte.
During the attack in September 1939, German shelling destroyed nearly all the equipment of the garrison’s sick room. Słaby was forced to use the most primitive, improvised methods to dress wounds. For example, he operated on Lieutenant Pająk without anaesthetic and used ordinary nail scissors to reconnect his damaged muscles. But despite the catastrophic hygienic conditions in the barracks cellars, all the wounded survived until surrender.
After capitulation, Captain Słaby served as a doctor in Stalag (prisoner-of-war camp) IA in Klein Dexen near Königsberg (today Kaliningrad Oblast). He looked after numerous prisoners and forced labourers, and saved many lives. After the war, Słaby joined the Border Guards and was promoted to major. In 1947 he was treacherously arrested, falsely charged with espionage and imprisoned in Cracow’s Montelupich prison. There he was most probably tortured, became very ill and died. He was buried at the military cemetery on Prandoty Street in Cracow.
Słaby was decorated posthumously with the Virtuti Militari Silver Cross.