558 : negotiations between the Avars and Justinian I.
567 : arrival of the Avars in Pannonia.
582 : the Avars take Sirmium.
584 : the Avars take Singidunum (mod. Belgrade). Attacks against Thessalonica, without success
586 : new unsuccessful assault of the Avars against Thessalonica
617 : negotiations of Herakleios with the Avars.
619 : Byzantium raises the tribute paid to the Avars.
Beginnings of June 626 : the Persians reach Chalcedon
29 June 626 : the Avars from Adrianople arrive in front of the Long Wall.
29 June 626 : the Avar khagan with his army arrives before Constantinople
30 June 626 : preparations for the siege.
31 July 626 : launch of the Avars’ assault against Constantinople
1-6 August 626 : clashes between the Avars and the Byzantines.
7 August 626 : final assault of the Avars against Constantinople. Defeat of the Avar army.