“Secrets of Great Ukrainians. Bohdan Khmelnytsky” is a documentary film. Bohdan Khmelnytsky (1596-1657) was a Ukrainian politician, commander, diplomat, leader of national liberation rebellions, creator of the Ukrainian Cossack state, hetman of the Zaporozhye Army. The authors of the project found new facts that allow us to take a completely different look at the majestic figure of this Ukrainian hetman.