Saint Isaac's Cathedral or Isaakievskiy Sobor () is a large architectural landmark cathedral that currently functions as a museum with occasional church services in Saint Petersburg, Russia. It is dedicated to Saint Isaac of Dalmatia, a patron saint of Peter the Great, who had been born on the feast day of that saint. It was originally built as a cathedral but was turned into a museum by the Soviet government in 1931 and has remained a museum ever since, with church services held in a side chapel since the 1990s. In 2017, the Governor of Saint Petersburg offered to transfer the cathedral back to the Russian Orthodox Church, but this was not accomplished due to the protests of St Petersburg citizens opposing the offer. History The church on St Isaac's Square was ordered by Tsar Alexander I, to replace an earlier structure by Vincenzo Brenna, and was the fourth consecutive church standing at this place. A specially appointed commission examined several designs, including that of the French-born architect Auguste de Montferrand (1786–1858), who had studied in the atelier of Napoleon's designer, Charles Percier. Montferrand's design was criticised by some members of the commission for the dry and allegedly boring rhythm of its four identical pedimented octastyle porticos. It was also suggested that despite gigantic dimensions, the edifice would look squat and not very impressive. The members of the commission, which consisted of well-known Russian architects, were also particularly concerned by necessity to build a new huge building on the old unsecure foundation. The emperor, who favoured the ponderous Empire style of architecture, had to step in and solve the dispute in Montferrand's favour. The cathedral took 40 years to construct, under Montferrand's direction, from 1818 to 1858. To secure the construction, the cathedral's foundation was strengthened by driving 25,000 piles into the fenland of Saint Petersburg. Innovative methods were created to erect the giant columns of the portico. The construction costs of the cathedral totalled an incredible sum of 1 000 000 gold rubles. Under the Soviet government, the building was stripped of religious trappings. In 1931, it was turned into the Museum of the History of Religion and Atheism, the dove sculpture was removed, and replaced by a Foucault pendulum. On 12 April 1931, the first public demonstration of the Foucault pendulum was held to visualize Copernicus's theory. In 1937, the museum was transformed into the museum of the