in 1127 and was crowned king in 1130, the fate of Naples hinged on Sergius' relations with the Sicilian court.

In 1131, Roger demanded from the citizens of Amalfi the defences of their city and the keys to their castle. When the citizens refused, Sergius initially prepared to aid them with a fleet, but the Admiral George of Antioch blockaded the port city with a larger fleet and Sergius submitted to Roger. According to the chronicler Alexander of Telese,