His mother, Karolina Veith, was the daughter of a Czech-German officer stationed at the Przemysl garrison.

In 1863, he married Jozefa de Wankowicz, a distant cousin and member of the Lis noble family.

In 1890, he helped initiate the "New Era" movement, dedicated to forging a rapprochement between Poles and Ukrainians in east Galicia.

After most of the other Ukrainophiles broke with the Poles in 1894, Vakhnianyn continued to seek compromise with them, and along with Oleksander Barvinsky was one of the founders of the "Catholic Ruthenian-Social Union", based on the all-Austrian Christian social movement.

He also wrote four novels and translated works by Nikolai Gogol and Ivan Turgenev.