This remarkable monument of Russian architecture, linking three centuries of art and religion, was the private chapel of the royal family. Its foundations were laid in the 14th century, and in the 15th century a triangular brick church in the early Moscow style was erected on the site. Partially destroyed by fire, it was rebuilt in the 16th century during the reign of Ivan the Terrible, when six gilded cupolas were added. Tsar Ivan would enter the church by the southeast-side porch entrance, built especially for him. He was married three times too many (for a total of six wives) and was therefore, under the bylaws of the Orthodox religion, not allowed to enter the church through its main entrance. The interior is decorated by brilliant frescoes painted in 1508 by the Russian artist Feodosy. The polished tiles of agate jasper covering the floor are said to be a gift from the Shah of Persia. Most striking of all is the chapel's iconostasis. The fine icons of the second and third tiers were painted by some of Russia's greatest masters—Andrei Rublyov, Theophanes the Greek, and Prokhor of Gorodets.