c. 40,000 Tatar horsemen[b] Crimean ambassador in Warsaw claim: Modern Estimates: 200,000+[6] The Fire of Moscow occurred on 24 May 1571, when the Crimean army[7] (c. 40,000 horsemen[4]) led by the khan of Crimea Devlet I Giray, bypassed the Serpukhov defensive fortifications on the Oka River, crossed the Ugra River into the Moscow suburbs, and rounded the flank of the 36,000–40,000 men[4] of the Russian army.

In 1561, Muscovites "received a letter from the Patriarch of Constantinople" (which turned out to be false[8]), asserting the rights of Ivan the Terrible to claim himself the Tsar.

The advanced regiment of Mikhail Vorotynsky and Pyotr Tatev stood on the Tagansky meadow, while the army of Vasily Tiomkin-Rostovsky was behind Neglinnaya.

During the battle, the Crimeans pushed back the Russians, Prince Belsky was wounded, and a fire rapidly spread through the city.

[11] The Crimean Tatar forces set the suburbs on fire on 24 May and a sudden wind blew the flames into Moscow and the city went up in a conflagration.

The unfolding events during the battle caused great distress within the army, with their wagons being nearly completely destroyed by fire on the streets of Moscow.

Despite these challenges, the number of troops recruited from local cavalry, which relied on the support of serving cities, did not experience a significant decrease, as evident from the campaign of 1572.

Following the devastating incidents, the authorities in Moscow contemplated the construction of a formidable stone barrier encompassing Bely Gorod, strategically designed to render it impervious to the relentless onslaught of the Tatar cavalry.

[18] [19] The campaign launched against Moscow had a significant impact on the foreign policy dynamics of the Russian state, resulting in a notable transformation in its international relations.