Medieval historians only recorded Muslim conquests reaching their own region

Evidence

Bede only notices the Muslim conquests as they reach the Western Mediterranean. He notes in his chapter on the reign of Constantine IV (668–85) that “Saracens invaded Sicily and returned to Alexandria with great booty” Emperor Justinian II (685–95) “made peace with the Saracens, by sea and by land, for ten years. But the Saracens took the province of Africa from the Roman Empire … and captured and destroyed Carthage.” — John V. Tolan, Saracens, 451