Furthermore, his grandfather, Mikolaj Dunin-Wasowicz, was a Chevau-léger during Napoleonic Wars, who fought in the Battle of Somosierra.

After graduation from military cadet school in Lobzow (now a district of Kraków), Dunin-Wasowicz became a professional officer of the Austro-Hungarian Army.

He fought the Russians in the area of Kielce, and on August 23 was sent back to Kraków, charged with training of additional cavalry units of Polish Legions in World War I.

In late November and early December 1914, he fought with his unit in the area inhabited by Hutsuls, and in January 1915, Dunin-Wasowicz 2nd squadron was transferred to Bukovina, to repel Russian invasion of this province.

He was buried at Rakowicki Cemetery in Kraków: mass funeral of uhlans killed at Rokitna took place on February 25, 1923.