In 1780, arrived in St. Petersburg and entered the service of the Grand Duke Pavel Petrovich; in 1784 was made court painter; and in 1785 - "designated" in academics for the painting of the portrait. (Kondakov)
Some researchers mentioned Willie, artist and architect, in connection with the design of the Mikhailovsky castle: "In the early 1780-ies Paul with his wife incognito (under the name of the princes of the North) are making a journey across European countries, and among the persons accompanying them as a consultant was a Swiss architect and painter, Willie, who told the heir to the Russian throne, the masterpieces of European architecture. Of special interest Paul called castle Caprarola near Rome, built by the architect Peruzzi in the XVI century by Pietro Farnese (future Pope Paul III), and, of course, the castle of the knights of Malta, called the castle of St. Michael. Thus, during the journey of a troubled teenage dream begins to take real shape and even associated with a particular name.
In 1784 Pavel Petrovich, together with arrived in Russia artist of Willie continue work on the project castle, which at that time was intended to Gatchina, as shown by one of the design sheets, where the building is already similar to the later castle, is adjacent to the Gatchina Palace buildings. A little later, to the development of project details is connected, Vincenzo Brenna, but the main architectural credibility (and ideological leader!) Paul still Bazhenov." (text S. S. Bartina)