Having frivolously spent his fortune and his wives (he was married twice), <...> fell into extreme need and was taken into trusteeship.The only son of Prosecutor General Pavel Yaguzhinsky and his wife Anna Gavrilovna, daughter of Chancellor Gavriil Golovkin.

"Yaguzhinsky is humble and constant, and studies very diligently from morning to evening, why is it necessary for him to have rest", Lanchinsky reported to Saint Petersburg.

"In Yaguzhinsky's wardrobe there was only one full set of outfit (hat, caftan, camisole, culottes, stockings, a pair of shoes and a sword).

[2] In August 1750, Yaguzhinsky expressed a desire to return to Russia, about which he wrote to the Empress: When I was here, I studied German and French with all diligence... geography, history, various exercises and mathematics.

[2] He also pointed out that he spent 60,000 on the development of state–owned factories, and demanded, if not compensation for these costs, then at least the return of the "box" with jewelry taken from his mother, not counting 66 items of silver utensils.

Although the German Miller, who kept a stocking factory, filed a complaint that the count was withholding his belongings in the amount of 17,180 rubles, the empress was not interested in a conflict with the higher nobility.

The only serf memoirist in the 18th century, Leonty Travin, wrote about Devals: It was quite well known that in Moscow, in the Pavlovian Estate, he tyrannized and ruined many to the end, and tortured others, keeping them in custody in the cellar; this foreshadowed us a general calamity.At the same time, it is known that Yaguzhinsky paid for the education of the serf musician Mikhail Matinsky, one of the first Russian composers, at his own expense.

His wife left her husband's house in the autumn of 1767 in order to protect her own dowry and the funds that Yaguzhinsky borrowed from her relatives from confiscation.

[4] In recent years, Count Yaguzhinsky lived in his own house on the Field of Mars, 5 with his second wife Varvara Saltykova (1749–1843), heiress of the village of Safarino on Troitskaya Road.

In the Church of the Annunciation of the Alexander Nevsky Lavra, a wall tombstone with a portrait bas–relief depicting the last Count Yaguzhinsky has been preserved.