During the opening stages of the Polish-Bolshevik War between December 1919 and April 1920, he served as the head of the 1st Detachment of the General Staff, responsible for organization and mobilization of forces.

In 1923, after a year of service at the post of commanding officer of the 26th Infantry Division, he was promoted to the rank of generał brygady.

He held that post until relieved on 16 September, and then took part in the battle of Lwów as a commander of one of the areas of defence of the besieged city.

After the capitulation of the Polish forces had been negotiated on 22 September 1939, Prich was to be released home along with other reserve and retired officers, which was a lie.

Among the Katyn victims were 14 Polish generals including Leon Billewicz, Bronisław Bohatyrewicz, Xawery Czernicki (admiral), Stanisław Haller, Aleksander Kowalewski, Henryk Minkiewicz, Kazimierz Orlik-Łukoski, Konstanty Plisowski, Alojzy Wir-Konas, Franciszek Sikorski, Leonard Skierski, Piotr Skuratowicz, and Mieczysław Smorawiński.