The earliest layers of Bukhara city culture are 2500 years old. It oldest monuments are Job well—Chashma-Ayub and citadel Ark. The version says that the name of the city comes from the Sogdian word “Bukharak”—a happy place. Local governors began coining in the 2nd century B.C. In the seventh century the Bukhara Union of Princedoms was headed by governors with a title of Bukhar-Hudat. In the early eighth century Arabian commander Kuteyba conquered Bukhara and constructed the first mosque in the city—Banu Hanzala. In the end of the 9th century Central Asian interfluve liberated itself from the domination of the Arabs a Bukhara became the capital of the Samanid Power. During the ninth and eleventh centuries under the Samanids and the Karakhanids the city was protected with new high walls.