International Association of Byzantine Studies (French: Association Internationale des Études Byzantines, AIEB) was launched in 1948 with Paul Lemerle as inaugural President. It is the International co-ordinating body that links national study groups.
It has published a bulletin from 1964.
Dionysios Zakythinos was chair between 1971-1976, and later president.
References
International Association of Byzantine Studies Wikipedia(Text) CC BY-SA