 and the name "Kankar" given to the lower Yaxartes by Persian geographer ibn Khordadbeh.Joseph Marquart, Omeljan Pritsak and Peter B.Golden have noted phonetic similarities between Kangju and Kengeres mentioned in the Orkhon inscriptions, the Kangarâyê in Transcaucasia, the city of Kengü Tarban, and the three Pecheneg tribes collectively known as Kangar mentioned by Constantine VII Porphyrogenitus.