This is an idea of TL that I could pursue later.
POD: Athalaric doesn't die in 534 AD.
There is no Gothic war.
Stronger than in OTL, the ERE is able to put up with the wars against Persia. Spania is still given to the Byzantines. The new province will be better defended than in OTL.
In the Balkans, Justinian uses the Avars against the Bulgars.
The Lombards settle in Illyria and Pannonia. The Padan plain is frequently invaded.
Helped by the Byzantines, the Aksumites conquer much of southwestern Arabia (Yemen, Asir, southern Hedjaz).