Saint Isaac's Cathedral

Saint Isaac's Cathedral  St Isaac's Cathedral (1818-1858) is one of the largest religious buildings in the world (height: 101.5 metres; base: over 10,000 square metres; diameter of the dome: about 25 metres).
The realization of this highly complex project did much to further the development of constructional engineering and applied art in Russia. The cathedral was consecrated in the presence of Alexander II on 30 May 1858 in a splendid ceremony with the Guards participating.
When Montferrand arrived in St Petersburg in 1816, the site of the cathedral was occupied by the third church dedicated to St Isaac of Dalmatia, on whose feast day Peter I was born. In the first wooden church (1710) Peter married Catherine I. The second was erected in masonry by Mattarnovy in 1717 and burnt down in the 1730s. The third was begun by Rinaldi in 1768 and completed by Brenna in the 1790s. This part-brick, part-marble edifice was so clumsy that the Synod requested its immediate reconstruction.
The exterior and interior decoration of the building was begun in 1841, when work on the load-bearing constructions was in the main complete. Models for the sculptures were created by such out-standing sculptors as Ivan Vitali,Piotr Klodt, Nikolai Pimenov, Philippe Lemaire and Alexander Loganovsky, who succeeded in creating an integral, harmonious ensemble. In designing the bronze reliefs that adorn the huge oak doors, Vitali took as his prototype the doors of the Baptistery in Florence created by Lorenzo Ghiberti (circa 1381-1455). In all 1,000 tonnes of bronze was used for the cathedral sculpture. Some works represent the earliest use any- where in the world of the galvanoplastic technique invented in 1838 by Boris Jacobi.
Main iconostasis
The three-tier central iconostasis takes the form of a gigantic marble wall,separating the main altar from the body of the church.
The iconostasis is embellished by twelve columns that seem to be monolithic. In actual fact they are bronze cylinders inlaid with rare semiprecious stone (two with Afghan lapis lazuli, ten with malachite) and topped with Corinthian capitals of gilded bronze. The icons in the lower two tiers are mosaics produced from designs by Timoleon Karl von Neff and Fiodor Briullov. The icons of the third tier were painted in oils on canvas by Semion Zhivago.
Paintings and Mosaics
Some of the foremost representatives of the Russian academic school were invited to work on the paintings for the cathedral - Karl Briullov, Fiodor Bruni, Vasily Shebuyev, and many others. The works were executed in oils on canvas then attached to the vaults, walls and piers. When low temperatures and high humidity began to threaten the paintings, Montferrand had the idea of replacing painted panels with mosaics and obtained Nicholas I's agreement. Several graduates of the Academy of Arts were sent to Rome to study the mosaic technique and the special workshop founded there was moved to St Petersburg in 1851. From that date until 1914 systematic work was carried out to replace the canvases with mosaics (and never completed).
In that period the Russian mosaicists developed over 12'000 shades of smal-tos (coloured glass). In 1862 some of the cathedral mosaics were displayed to great acclaim at the international exhibition in London and Russian smalto-making techniques were acknowledged the best in the world.
Gallery of St. Isaac's Cathedral.