Regarding the foundation of the medieval city, there are some outstanding questions that are not historically based, like the suggestion that Melfi was founded in 1018 by Catapan Basilius Bojoannes (Catapan of Italy from 1017 to 1027), a hypothesis that G. Fortunato considers to be a “legend”:
"It is a legend that Catapan Basilius Boioannes had founded Melfi in 1018, the city was already seat to the merchants of Amalfi, and as Venosa and Lavello for Jewish bankers. He only encircled the city with walls […]” .
This is also confirmed by recent studies that prove that Catapan Basilius Boioannes in the 11th century only founded some "kastra [fortresses] of Melfi” .
Even with the advent of the Lombards Melfi was fortified because of its strategic location on the edge in the domain of the Byzantines. In the ninth century it came into the hands of the Byzantines, becoming, however, a reason for a clash with the Lombards.
Normans in Melfi
During the 11th century Melfi was for many years the capital of the Normans, and it was here that five ecumenical councils were organized between 1059 and 1101, including that in which the First Crusade (1089) was decided.
The Normans also decided to build a new castle, new walls and the cathedral at this time..