St. Michael's Castle (Russian: Миха́йловский за́мок, Mikhailovsky zamok), also called the Mikhailovsky Castle or the Engineers' Castle (Russian: Инженерный замок, Inzhenerny zamok), is a former royal residence in the historic centre of Saint Petersburg, Russia. St. Michael's Castle was built as a residence for Emperor Paul I by architects Vincenzo Brenna and Vasili Bazhenov in 1797-1801. The castle looks different from each side, as the architects used motifs of various architectural styles such as French Classicism, Italian Renaissance and Gothic.
St. Michael's Castle was built to the south of the Summer Garden and replaced the small wooden palace of Empress Elizabeth Petrovna. Afraid of intrigues and assassination plots, Emperor Paul I disliked the Winter Palace where he never felt safe. Due to his personal fascination with medieval knights and his constant fear of assassination, the new royal residence was built like a castle around a small octagonal courtyard. The building with rounded corners was surrounded by the waters of the Moika River, the Fontanka River and two specially dug canals (the Church Canal and the Sunday Canal), transforming the castle area into an artificial island which could only be reached by drawbridges.
Construction began on 26 February (N.S. 9 March), 1797 and the castle was solemnly consecrated on 8 November 1800, i.e. on St. Michael's Day in the Eastern Orthodox calendar, though finishing work on the interior continued until March 1801. In 1800, the bronze equestrian Monument to Peter the Great was set up in front of the castle. This statue had been designed during Peter the Great's lifetime and later, with the casting being completed in 1747 by the architect Bartolomeo Rastrelli. By order of Paul I, the inscription "From Great Grandson to Great Grandfather" was made on the pedestal that is decorated with bas-reliefs depicting scenes of two Russian victories over Sweden during the Great Northern War.
Ironically, Paul I was assassinated only 40 nights after he moved into his newly built castle. He was murdered on 12 March 1801, in his own bedroom, by a group of dismissed officers headed by General Bennigsen. The conspirators forced him to a table, and tried to compel him to sign his abdication. Paul offered some resistance, and one of the assassins struck him with a sword, and he was then strangled and trampled to death. He was succeeded by his son, Emperor Alexander I, who was actually in the palace at the time and was informed of his accession by General Nicholas Zubov, one of the assassins.