The Khazars themselves first campaigned in the Caucasus during the Byzantine–Sassanid War of 602–628, as subjects of the Western Turkic Khaganate. The Turks sacked Derbent and joined the Byzantines in their siege of Tiflis. Their contribution proved decisive for the eventual Byzantine victory in the war. For a few years afterwards, the Khazars exercised some control over Caucasian Iberia (approximately modern Georgia), Caucasian Albania/Arran (modern Republic of Azerbaijan) and Adharbayjan (modern Iranian Azerbaijan), while the western half of Transcaucasia, i.e Armenia, was in Byzantine hands. However, after the death of the Khazar or Western Turkic ruler in an internal conflict , the Khazar activity in eastern Transcaucasia ceased.