 Porphyrogenitus wrote that the Kabars – a group of Khazars who rebelled against the Khagan – joined the Magyars in Etelköz at an unspecified time , suggesting that the Magyars had got rid of the Khagan 's suzerainty . The Kabars were organized into three tribes , but a single chieftain commanded them . Porphyrogenitus also wrote that the Kabars " were promoted to be first " tribe , because they showed themselves " the strongest and most valorous " of the tribes . Accordingly , the Kabars formed the Magyars ' vanguard , because nomadic peoples always placed the associated tribes in the most vulnerable position . 
