The work on the interior decoration of St Isaac’s Cathedral caused the revival of the mosaic art in Russia in the 19th century. There are 62 mosaic pieces here covering an area of 500 sq.m. The work on mosaics began in 1851 and continued up to 1941.
The mosaics in the bottom tier of the main iconostasis were the first to be made. They were based on sketches by T.A.Neff, and included “St Catherine” by A.N. Frolov, E. Lindblat and F. Gartung, as well as “St. Nicholas of Myra” by I.C. Shapovalov, M.P. Muravyov and M.I. Shchetinin.
The icons in the second tier of the main iconostasis feature the mosaic copies, as well as the mosaic images of “The Passions of Christ” and the four evangelists in pendentives.
A brilliant example of the mosaic replacement is the icon “The Last Supper”, executed from S. Zhivago’s sketches by mosaic artists I.P. Kudrin, I.A. Laveretsky, M.P. Muravyov, I.A. Pelevin and N.Y. Silivanovich. This work reflects an influence of the famous fresco by Leonardo da Vinci. In creating “The Last Supper” the optical technique of colour mixing was used. To achieve a proper colour shade, coloured pieces of smalt were assembled to merge in a special way that would allow them to produce the necessary colour when viewed from a distance.
The mosaics beautifully render the cold glittering of metal, satin clothes, and the warmth of human hands. In order to convey the richness of painting colours, mosaic artists had to use over 12,000 different shades of smalt.
The mosaics in St Isaac’s Cathedral are distinguished for their perfect craftsmanship. At the 1862 World Exhibition held in London they received the highest praise. The experts noted that the Russians “reached perfection in the making of smalt unmatched elsewhere in Europe”.