While Ivan was a child, armies of the Kazan Khanate repeatedly raided northeastern Russia.
In the 1530s, the Crimean khan formed an offensive alliance with Safa Giray of Kazan, his relative.
When Safa Giray invaded Muscovy in December 1540, the Russians used Qasim Tatars to contain him.
After his advance was stalled near Murom, Safa Giray was forced to withdraw to his own borders.

The reverses undermined Safa Giray's authority in Kazan.
A pro-Russian party, represented by Shahgali, gained enough popular support to make several attempts to take over the Kazan throne.
In 1545, Ivan mounted an expedition to the River Volga to show his support for the pro-Russians.

In 1551, the tsar sent his envoy to the Nogai Horde, and they promised to maintain neutrality during the impending war.
The Ar begs and Udmurts submitted to Russian authority as well.
In 1551, the wooden fort of Sviyazhsk was transported down the Volga from Uglich all the way to Kazan.
It was used as the Russian place d'armes during the decisive campaign of 1552.

On 16 June 1552, Ivan led a strong Russian army towards Kazan.
The last siege of the Tatar capital commenced on 30 August.
Under the supervision of Prince Alexander Gorbaty-Shuisky, the Russians used battering rams and a siege tower, undermining and 150 cannons.
The Russians also had the advantage of efficient military engineers.
The city's water supply was blocked and the walls were breached.
Kazan finally fell on 2 October, its fortifications were razed and much of the population massacred.
Many Russian prisoners and slaves were released.
Ivan celebrated his victory over Kazan by building several churches with oriental features, most famously Saint Basil's Cathedral on Red Square in Moscow.
The fall of Kazan was only the beginning of a series of so-called "Cheremis wars".
The attempts of the Moscow government to gain a foothold on the Middle Volga kept provoking uprisings of local peoples, which was suppressed only with great difficulty.
In 1557, the First Cheremis War ended, and the Bashkirs accepted Ivan IV's authority.

In campaigns in 1554 and 1556, Russian troops conquered the Astrakhan Khanate at the mouths of the Volga River, and the new Astrakhan fortress was built in 1558 by Ivan Vyrodkov to replace the old Tatar capital.
The annexation of the Tatar khanates meant the conquest of vast territories, access to large markets and control of the entire length of the Volga River.
Subjugating Muslim khanates turned Muscovy into an empire.

After his conquest of Kazan, Ivan is said to have ordered the crescent, a symbol of Islam, to be placed underneath the Christian cross on the domes of Orthodox Christian churches.
While Ivan was a child, armies of the Kazan Khanate repeatedly raided northeastern Russia. In the 1530s, the Crimean khan formed an offensive alliance with Safa Giray of Kazan, his relative. When Safa Giray invaded Muscovy in December 1540, the Russians used Qasim Tatars to contain him. After his advance was stalled near Murom, Safa Giray was forced to withdraw to his own borders.
The reverses undermined Safa Giray's authority in Kazan. A pro-Russian party, represented by Shahgali, gained enough popular support to make several attempts to take over the Kazan throne. In 1545, Ivan mounted an expedition to the River Volga to show his support for the pro-Russians.
In 1551, the tsar sent his envoy to the Nogai Horde, and they promised to maintain neutrality during the impending war. The Ar begs and Udmurts submitted to Russian authority as well. In 1551, the wooden fort of Sviyazhsk was transported down the Volga from Uglich all the way to Kazan. It was used as the Russian place d'armes during the decisive campaign of 1552.
On 16 June 1552, Ivan led a strong Russian army towards Kazan. The last siege of the Tatar capital commenced on 30 August. Under the supervision of Prince Alexander Gorbaty-Shuisky, the Russians used battering rams and a siege tower, undermining and 150 cannons. The Russians also had the advantage of efficient military engineers. The city's water supply was blocked and the walls were breached. Kazan finally fell on 2 October, its fortifications were razed and much of the population massacred. Many Russian prisoners and slaves were released. Ivan celebrated his victory over Kazan by building several churches with oriental features, most famously Saint Basil's Cathedral on Red Square in Moscow. The fall of Kazan was only the beginning of a series of so-called "Cheremis wars". The attempts of the Moscow government to gain a foothold on the Middle Volga kept provoking uprisings of local peoples, which was suppressed only with great difficulty. In 1557, the First Cheremis War ended, and the Bashkirs accepted Ivan IV's authority.
In campaigns in 1554 and 1556, Russian troops conquered the Astrakhan Khanate at the mouths of the Volga River, and the new Astrakhan fortress was built in 1558 by Ivan Vyrodkov to replace the old Tatar capital. The annexation of the Tatar khanates meant the conquest of vast territories, access to large markets and control of the entire length of the Volga River. Subjugating Muslim khanates turned Muscovy into an empire.
After his conquest of Kazan, Ivan is said to have ordered the crescent, a symbol of Islam, to be placed underneath the Christian cross on the domes of Orthodox Christian churches.
Ivan the Terrible