Grand Duke Yaroslav Vladimirovich - the only Russian ruler - went down in history with the nickname Wise. The time of his reign is assessed by scientists as the golden age of Ancient Russia: the cessation of civil strife and the restoration of the territorial integrity of the state, victory over external enemies, powerful construction in all cities, the transformation of Kyiv in beauty and wealth into a rival of Constantinople, the foundation of schools and the spread of literacy among different strata of the population. How did this person, who experienced constant pain from a congenital illness, overcome his suffering and have time to do so much in those conditions for the prosperity of our homeland strengthening its international authority?