In 1715-1724 a two-storey palace was built with a central section flanked by two projecting bays; the original architect is unknown, but further construction followed the designs of Le Blond and Niccol Michetti. Empress Elizabeth (reigned 1741-1762) commissioned Bartolomeo Francesco Rastrelli to enlarge the palace. Between 1745 and 1755 he raised the building to three storeys and added three-storey wings facing the Upper Park, with galleries ending in two domed pavilions. Of the early 18th-century interiors, the Tsars study, with oak panelling in Rococo style by Nicolas Pineau, remains unchanged, as does the oak staircase. Rastrelli designed five staterooms and a series of reception-rooms, which were sumptuously decorated with gilded wood-carving, ceilings painted by Bartolomeo Tarsia, Ivan Vishnyakov and others, mirrors, decorative parquet floors, vases and statues. In 1763 the Chinese lobbies were decorated to a design by Jean-Baptiste Vallen de la Motte, with lacquered panels and paintings by A. Perizinotti and the brothers Aleksey Belsky (1730-1796) and Ivan Belsky (1719-1799). In the second half of the 18th century the state Chesma Hall, Throne Room, White Dining-room and other ceremonial reception-rooms were reworked in a Neo-classical style by Yury Felten and Vallen de la Motte.