Saint Basil's Cathedral was built under Ivan the Terrible's orders

To celebrate the conquest of Kazan, Ivan had St. Basil's Cathedral built in Moscow. The Cathedral of Vasily the Blessed, often known as Saint Basil's Cathedral, is an Orthodox church in Moscow's Red Square and one of Russia's most popular cultural landmarks. The Cathedral of the Intercession of the Most Holy Theotokos on the Moat, now a museum, is formally known as Pokrovsky Cathedral. Saint Basil's Cathedral was built under Ivan the Terrible's orders between 1555 and 1561 to commemorate the conquering of Kazan and Astrakhan. Until the erection of the Ivan the Great Bell Tower in 1600, it was the tallest building in the city.

The original Trinity Church, subsequently Trinity Cathedral, had eight chapels organized around a ninth, central chapel dedicated to the Intercession; a tenth chapel was built in 1588 over the burial of the venerated local saint Vasily (Basil). In the 16th and 17th centuries, the church was regarded as the earthly image of the Heavenly City (as were all churches in Byzantine Christianity) and functioned as an allegory of the Jerusalem Temple in the annual Palm Sunday parade attended by the Patriarch of Moscow and the Tsar.

There is a legend that he was so taken with the edifice that he blinded the architect, Postnik Yakovlev so that he could never design anything as beautiful again. Postnik Yakovlev, on the other hand, went on to build several churches for Ivan and the Kazan Kremlin walls in the early 1560s, as well as the chapel over St. Basil's grave, which was built to St. Basil's Cathedral in 1588, several years after Ivan's death. Although that name has been connected with more than one architect, it is thought that the principal architect is the same individual.