He was born on 20 April 1860. During World War I, he was in France, where he worked for a committee recruiting Poles living in France to join the army. In parallel, he actively sought support for the Polish cause among French politicians. Later, he briefly stayed in England, where he continued his work for the independence of Poland. During and after the war, still as an émigré in France, he published many articles in French and English newspapers, in which he argued for an independent and strong Poland as an important element of maintaining the balance of power in Europe. After returning to Poland in 1921, Tarnowski was very critical about the situation of the country. He contributed to “Kurier Codzienny”, “Czas”, “Dzień Polski”, “Dziennik Poznański”, “Kurier Warszawski”, as well as to “Journal de Pologne”. He died in Kraków, on 21 March 1928, and was buried in the Rakowicki Cemetery.