The original Palace was built in years 1623-1630 by Albrecht von Wallenstein, Duke of Mecklenburg (1583-1634), who made his name and fortune as the Commander-in-Chief of the Imperial forces in the Thirty Years War. To obtain a suitable site, he had to purchase 23 houses and three gardens. The magnificent main hall rises to a height of two stories tall with a ceiling fresco depicting Wallenstein himself as Mars, the God of War, riding in a triumphal chariot. Emperor Ferdinand II however, feared Albrecht of Wallenstein’s calculating mind and had him assassinated in 1634. His widow sold it to his nephew and it remained in the Wallenstein family until 1945. After World War II, the palace became Czechoslovak state property and was renovated to house government offices. Today, the Senate of the Czech Republic operates out of the main palace buildings. The Riding School is used to display art as a branch of the National Gallery in Prague. The challenging restoration of the main building began in mid-1999. The most valuable parts of this building in historical and artistic terms are the Main Hall, the Knights' Hall, the Antechamber, the Audience Hall and the Mythological and Astronomical Corridors.