Sarkel was a large limestone-and-brick fortress in what is now Rostov Oblast of Russia, on the left bank of the lower Don River.
Aerial photo of the excavations conducted at Sarkel in the 1930s.
Turkic Tamgas on some of the bricks from Sarkel
Theophilos was the Byzantine Emperor from 829 until his death in 842. He was the second emperor of the Amorian dynasty and the last emperor to support iconoclasm. Theophilos personally led the armies in his long war against the Arabs, beginning in 831.
Theophilus, in the Chronicle of John Skylitzes
Theophilos on a coin of his father, Michael II, founder of the Amorian/Phrygian dynasty
Emperor Theophilos argues with the iconophile monk Lazarus.
Theophilos ordering the urban prefect to execute his father's co-conspirators, who were involved in the murder of Leo V