Dalmatia or Slavonia, 9th century
Part of a church gable and architrave
Zadar Archeological Museum
The motif of peacocks flanking a cross goes back to at least the 4th century. The peacocks symbolize immortality.
The inscription reads BRANIMIR O COM[es] DUX CRUATORUM COGIT[ATUS], "Count Branimir, considered Duke of the Croats." This is the oldest monument bearing the name of Croatia. Branimir ruled in the 9th century.
The museum label says this fragment is from "Šopot near Benkovac." There is a Benkovac on the Dalmatian coast and another in Slavonia. According to Wikipedia "Šopot" is an old Slavic word for "spring" and the name of three different villages in Albania.
This image in full resolution
More of crosses and crucifixes
Photographed at the museum by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.