The citadel in Moscow, centre of administration of the Russian government and formerly of the Soviet Communist government. Covering an area of 28 hectares, its palaces, churches, and monuments are surrounded by a wall 2235 m (7333 feet) in length. The building of the Kremlin began in 1156 when Prince Yuri Dolgoruky ordered a wooden fort to be built on Borovitsky Hill. This later became the residence of the Grand Dukes of Moscow and the site where Russian emperors and empresses came to be crowned.