The Ivan the Great Bell Tower (1505 – 1508; architect – Bon Fryazin) was constructed of brick and white stone on the site of the dismantled church of St. Ivan Climacus of 1329, so called "under-the-Bell" type.
The initial bell tower was a three-story structure 60 meters in height, based on the foundation of the church of St. Ivan Climacus. The two lower tiers were in the shape of an elongated octahedral tower completed by open galleries, while the moderate third tier consisted of one open gallery for small bells and was crowned by a small cupola
In 1600, on the orders of Tsar Boris Godunov, the Bell Tower was raised to its present height and finished with a gilded dome, as commemorated by the gilded inscription on the blue background just under the dome's base. At the same time the tier of the carinated kokoshniks (corbel arches) was created to connect the octahedron of the third floor to the drum of the cupola thereby emphasizing the rocket-like projection of the bell tower.
As a result, the height of the Ivan the Great Bell Tower grew to 81 meters (while the white-stone basement of the bell tower remained upon its original octahedral shaped base at a diameter of 25 meters, sunk but 4,3 meters from the surface of Cathedral Square.)
From the beginning, the walls of the Ivan the Great bell tower were painted brick red, lending the white-stone details a more impressive hue and revealing the skeleton of the building's proportions. It is believed that in 1532-1543, the belfry was adjoined to the tower and the larger bells added under the supervision of the Italian immigrant architect Petrok Maly.
Such theories have not met without controversy, however. According to the architectural historian S. Podyapolsky, Petrok Maly was responsible for construction of the nearby Resurrection church, but not the belfry. Supporters of this view note the church was completed in 1552 - after Petrok Maly's departure from Moscow. Indeed, writings and observations about the church in the mid 17th century come largely thanks to foreigner visitors to Moscow at that time – including Henrich Staden, who served as oprichnik to Ivan the Terrible in 1560s , and Adam Oleary, who passed through the Russian capital on his way to Persia.
Then as now, visitors cannot fail to be impressed the huge bell located between the church and the Belfry of Ivan the Great tower. According to legend, a wooden belfry initial housed the Great Bell when it was cast in the time of Boris Godunov.
In the second half of the 17th century the church was refitted with a stone belfry built in the Pskov type. In 1624 the Patriarch Filaret ordered one more belfry added to the structure and named it the Filaret Annex (architect B.Ogurtsov).
In 1812 both structures were detonated under the orders of Napoleon, only to rise again (with a number of new Classicism features) in 1814-1815 under a reconstruction overseen by D.Gilardi, I.Egotov and L.Ruska. Finally, the high porch from the West facade of the belfry was attached in 1849-1852 under the design of K.Ton. Throughout, the Bell Tower of Ivan the Great has stood tall.
Today, the belfry of Ivan the Great contains 21 bells – among which the Great Assumption bell (cast by the 19th century masters Zavyalov and Rusinov) is the mightiest of all Kremlin bells. The bell itself weighs 4000 "poods" (a 19th century measurement weighing approximately 65,5 tons).