The paper will explore the manner in which Cyril of Alexandria acquired his status as a norm of orthodoxy in the context of the council of Chalcedon. It is quite undisputed, that Cyril was seen as the most important pillar of orthodoxy (after the Nicaenum) at the council of Chalcedon. Less studied is the way he got this importance and what the reference to Cyril meant. The study will explore the significance of the antiochene use of the conciliar letters of Cyril as norm of orthodoxy. It further wants to question the dissolution of the pattern of Antiochene and Alexandrian theology or schools for a homogenized picture of Chalcedon as a Council of "mainstream Cyrillians".