Located within the Kremlin fortress, the Orthodox cathedral served as the burial site for more than 40 Russian tsars and princes over the centuries. While the body of Grand Prince Donskoy was known to lie there, its discovery last month in a crypt by the southern wall surprised historians, who had previously believed it was located elsewhere in the building.

Putin lit a candle inside the frescoed cathedral and stood beside the white-stone sarcophagus as experts explained how they identified the remains as those of the 14th-century prince, according to the RIA news agency. The Russian Orthodox Church announced the discovery on Tuesday, stating that the well-preserved remains were nearly complete and belonged to a man just under 180 cm (5 feet 11 inches) tall who died of natural causes between the ages of 35 and 45.

"All these characteristics correspond with written sources and historical testimony concerning the life and death of the grand prince," the Church said.

Donskoy died in 1389 at the age of 39, having ruled the principalities of Muscovy and Vladimir, which later became the core of the Russian state. A prominent figure in Russian history, Donskoy oversaw the construction of the first stone Kremlin fortress, expanded the territory of Muscovy, and routed forces of the Mongol horde in a famous battle near the Don river in 1380.