This excerpt from Robert Elsie shows that Albanians presence in Italy predates the Arberesh migration of the 15th century. What is odd is that they are not mentioned as being in Albania until a century later.
http://www.albanianhistory.net/texts15/AH1038.html
1038, 1042, 1078
Michael Attaleiates:
The First Byzantine References
Michael Attaleiates was a Byzantine lawyer and historian who rose to high office under the emperors Romanus IV (r. 1067-1071) and Michael VII (r. 1071-1078). His 'History', covering the years 1034-1079, is a largely eyewitnessed account of political and military events in the Byzantine Empire. It was during this period that the Byzantine Greeks first took note of the Albanians as a people.
When the Emperor Michael (1), who passed away in piety and whose home is known to have been the province of Paphlagonia, took up the sceptre of the Byzantine Empire, the Agarene (2) people in Sicily in the West were defeated by Byzantine naval and land forces.
And had not the well-known George Maniakes, who had been entrusted with the general command, been eliminated on the slanderous accusation that he was hungry for power, and had not the military command of the war been transferred to others, that large and renowned island, blessed with large cities knowing no lack of precious goods, would still be under Byzantine control. Now, however, jealousy has destroyed not only the man and his endeavours, but also that enormous undertaking (3). For when subsequent commanders made base and shameful plans and decisions, not only was the island lost to Byzantium, but also the greater part of the army. Unfortunately, the people who had once been our allies and who possessed the same rights as citizens and the same religion, i.e. the Albanians and the Latins, who live in the Italian regions of our Empire beyond Western Rome, quite suddenly became enemies when Michael Dokenianos insanely directed his command against their leaders...
Constantine IX Monomachos (4) proved to be more benevolent on the imperial throne than his predecessor. He conveyed imperial honours and gifts to almost everyone with ambition, and delighted his subjects. Suddenly storm clouds gathered in the West and threatened him with nothing less than destruction and expulsion from the throne. The aforementioned George with the surname Maniakes, thirsting for blood, began an uprising in the Italian part of the Empire with Byzantine and Albanian soldiers there
(1) Michael IV (r. 1034-1041).
(2) i.e. the Arabs.
(3) i.e. the recapture of Sicily in 1038-1040.
(4) Constantine IX (r. 1042-1055).
[Extracts from: Michaelis Attaliotae: Historia, Bonn 1853, p. 8, 18, 297.
Translated by Robert Elsie.
First published in R. Elsie: Early Albania, a Reader of Historical Texts, 11th - 17th Centuries,
Wiesbaden 2003, p. 4-5.]