Avar Khaganate
The Avar Khaganate (567–804), who may have included Rouran elements after the Göktürks crushed the Rouran ruling Mongolia, also used this title. The Avars invaded Europe, and for over a century ruled the Carpathian region. Westerners Latinized the title "Khagan" into "Gaganus" (in Historia Francorum), "Cagan" (in the Annales Fuldenses), or "Cacano" (in the Historia Langobardorum).