In 1897, the Russian historian Vasily Klyuchevsky helped him to obtain a position as a lecturer on the Zaporozhian Cossacks at Moscow University.

In 1902, when he was offered a position as Director of the Yekaterinoslav Historical Museum in modern-day central Ukraine, he gladly accepted and remained there to the end of his life.

As a historian, Yavornytsky displayed a romantic-antiquarian approach to his subject and was a conscious follower of his predecessor Mykola Kostomarov.

Yavornytsky commissioned the best Ukrainian and Russian artists of his time (Opanas Slastion, Serhii Vasylkivsky, Nikolai Samokish, and Ilya Repin) to illustrate his various books, which were sometimes works of art in themselves.

During the Holodomor (the Ukrainian famine of 1932–33), he felt compelled to give away artifacts from his collections to obtain food for starving local peasants and others.

[citation needed] Materials about him began to appear, and in the early 1970s a four volume collection of his works was prepared for publication, supported by museum director Horpyna Vatchenko.

[6] Political circumstances again prevented this from happening, but with the advent of the Perestroika reforms in the late 1980s, new materials began to appear and his major works were republished.

Repin consulted Yavornytsky during his work on the painting and made use of several artifacts from the historian's collection to use as accurate models.