because Robert Guiscard was named a "duke" by Pope Nicholas II.

Salerno was conquered in 1077 by the Normans, and these territories were added to the Duchy of Apulia and Calabria and with this conquest, the Normans controlled all of continental southern Italy, with the exception of the small Duchy of Naples. The next year, the capital was moved from Melfi to Salerno, and the Normans