One wing was demolished and rebuilt, later becoming the Russian Museum of Ethnography, while a new extension, the Benois wing, was added in the 1910s. The palace was designed as a residence for Grand Duke Michael Pavlovich, youngest son of Emperor Paul I. At Paul's order, several hundred thousand rubles were to be set aside annually for the construction of the palace from 1798 onwards. In 1801, Paul was overthrown and killed in a palace coup, and his heir ascended to the throne as Alexander I. The new emperor decided to carry out his father's wishes and gave his approval to the construction of the new palace when Michael was 21. By this time some 9 million rubles had been accumulated. The designs were drawn up by Carlo Rossi in 1817. At first the site of the Vorontsov Palace was proposed and then the site of the Chernyshev residence, which later became the site of the Mariinsky Palace. Both options were rejected by Alexander I as being unnecessarily expensive and complex, instead selecting a new site in the city centre for development. The site eventually chosen was a space that had previously seen little development, between the confluence of the Fontanka and Moyka Rivers, the Griboyedov Canal and Nevsky Prospect. It had been used as garden and hunting space, with Empress Elizabeth's Summer Palace, and later Emperor Paul's Mikhailovsky Castle being located nearby. Rossi set out to develop a new architectural ensemble, which would include not only a new palace, but a square and two new streets, and . Two existing streets, Sadovaya and , were to be extended and included in the overall architectural ensemble. In early April 1819, the "Commission for the construction of the palace of Grand Duke Mikhail Pavlovich" was created. The ceremonial laying of the foundation took place in summer that year, with construction beginning on 26 July. Architect Adam Menelaws also laid out a garden for the palace overlooking the Field of Mars, which became known as the Mikhailovsky Garden. The masonry was the responsibility of , and . As was common with Russian building projects, construction work was only carried out in the warm seasons to ensure the work was reliable and durable, while the winter was spent collecting building materials and working on designs and calculations. The main core of the palace was built between 1819 and 1820, with the wings added the following year; by the end of 1822 the bulk of the construction was finished. The interior designs and decorations were completed over the next two years.