Defined by contemporaries as the 'Two Eyes' of the Earth, this suzerain order aimed to hierarchically organize those considered as 'barbarians'. This period of late antiquity is rarely considered within the discipline of International Relations (IR) but, through an English School approach, Blachford examines the diverse suzerain order of late antiquity as 'barbarous' nomadic tribes challenged the hierarchical ambitions of two rival empires who both claimed a unique role in the maintenance of world order.