This is the first of three papers published in this issue of the Lekarz Wojskowy (Military Physician) magazine dedicated to an outstanding military physician, Lt. Col. Konstanty Świder MD, PhD, forgotten in Poland. The paper presents his lineage, school years and studies, at the Physician Department of the Warsaw University and at the Medical Cadets School in Warsaw. The beginning of Świder’s career as a professional military physician in Poland, his fate after the outbreak of the WWII in September 1939 – time he spent in Soviet captivity, his military service in the Anders’ Army in the Soviet Union, in the Middle East, and during the Italian Campaign, and his contribution to building a psychiatric support system for soldiers of the Polish Armed Forces in the West are described. The last part of the paper describes the course of Dr. Konstanty Świder’s professional stabilization as an immigrant in the USA and his activity in the Polish diaspora in Chicago up to his premature death in 1965. Moreover, examples of Dr. Świder’s literary work and information on the status and professional activity of his children in the USA are presented.