St. Isaacs Cathedral

The original cathedral was the work of Antonio Rinaldi. It was begun in 1768 and was only partially completed by 1802. Eventually in 1816, Alexander I appointed a french architect, Auguste  Montferrand, to completely rebuild the cathedral (he was also responsible for St. Alexander’s Column).

He designed the church in the Neoclassical style, and the somewhat plain exterior does not hint at the ostentatious and elaborate interior decoration.

 St. Isaacs Cathedral (Isaakievskiy Sobor) was constructed over a period of 40 years between 1818 and 1858, and remains one of the most prominent features on the skyline of St. Petersburg.

The foundation work alone took more than 5 years, in part because a slab foundation was used in addition to the traditional wooden piles.

Another time-consuming task was obtaining the 48 granite columns for the main portico. It took 10 years to receive all of them from Finland, then a further 2 years to raise them to their full 51 meter height, and 4 more years to polish them all. Additionally, each column was shaped and finished on site using a gigantic lathe of Montferrand’s own design.

The cathedral’s most obvious feature, the massive dome, featured novel design techniques. Montferrand elected not to use the traditional method of a steel-framed exterior dome supported by a masonry inner dome. Montferrand’s system (only the 3^rd example of such a technique) consisted of 3 metal domes, with the center dome supporting the lightweight interior and exterior metal domes. Using this system subtracted 4760 metric tons from the overall dome weight, and saved 2 million roubles.

Finally, decorating the cathedral took 16 years, with the official cathedral opening taking place on May 30^th, 1858, marking the 186^th birthday of Peter the Great.

In the 1930s, St. Isaac’s was converted into a museum, and church services are now only held on major church occasions.