Tiberius II Constantine - AE Decanummium, 578-582 AD. Antioch
Size:  17mm  Weight:  3.64 grams
Obverse:  . ..ANT.., illegible legend, crowned, mantled bust facing, with cross on crown, holding mappa and eagle-tipped sceptre
Reverse:  Large X, ANNO to left, cross above, VII to right, Q-shaped e below.

SB 457, MIB 59.

Thanks to Dane Kurth for the identification!