The Duke’s state apartments are located in the Palace’s central building, and they comprise ten rooms with the view to the south. Five rooms display interiors pertaining to the period of Duke Ernst Johann’s reign; they have partially preserved two ornamental parquet floors, oak-wood panels and doors from the first construction period. Four rooms are devoted to Duke Peter and are arranged in neoclassical style. Five of the Duke’s state apartments feature ceiling paintings by Francesco Martini and Carlo Zucchi. Four rooms have white ceiling decorations, while two rooms are adorned with stucco decorations on the background of stucco marble made by Johann Michael Graff. By 2011 the restoration was competed in nine rooms.
The Rose Room is devoted to a theme of the Goddess of Spring and Flowers, Flora, who is depicted in the ceiling painting. This theme is developed on the walls where colourful stucco flower garlands adorn stucco marble panels. The parquet of the Rose Room dates back to 1739.
In the Dutch Salon emphasis is placed on paintings. In the 18th century, it was mainly works by Dutch masters that were put on display in Rundāle, among them Rembrandt’s painting Simeon and Anne in the Temple. The room also displays two chairs presented by Duke Peter to the Church of Sāti.
The room with governors’ portraits exhibits portraits of rulers who were related to the history of Courland. The stove in the corner of the room is one of the original stoves.
The Duke’s Bedroom featuring the state bed is located in the very centre of the building following the tradition of Versailles. The theme of the ceiling painting is Upbringing of Amor. The stoves made by Gottfried Kater, a potter from Danzig (Gdańsk), date back to 1740. The parquet floor, made in 1739 according to Rastrelli’s design, has been restored thanks to the financial support of Prince Ernst Johann Biron von Curland.
The ceiling in the Reception Room displays the myth of Venus and her beloved Adonis. The portrait of Duke Peter, created by the Courland court painter Friedrich Hartmann Barisien, gives a sense of his presence. The black lacquer commode made by Jean-Henri Riesener, the famous French court cabinet-maker, is the most valuable piece of furniture in the Museum’s collection.
The Italian Salon reflects Duke Peter’s love for Italy, where he had spent a considerable amount of time. He had even established a scholarship for students of the Bologna Academia of Arts. Impressions of Italy are conveyed by Giovanni Battista Piranesi’s engravings and a commode from Milan. The room also features one of the eight original tile stoves.
The Marble Hall served as the Duke’s dining room. The busts of Duke Peter, Duchess Dorothea and their daughters stand out against the background of stucco marble walls in grey and bluish colours. The ceiling cove is decorated with unusually blue festoons of flowers. Here one can also see items of the porcelain set ordered by Duke Peter from the Berlin KPM factory. The parquet floor of this room is yet to be restored.
The Billiard Room at the western end of the Duke’s state apartments was equipped with the billiard table and several card tables. The present billiard table has been made after the original design dating from 1770. The ceiling painting of the room is devoted to a theme of the Apple of Discord. The parquet floor has survived from the 1760s.