The Battle of Nocera was a significant military confrontation between Ranulf II, the Count of Alife, and Roger II, the Duke of Sicily. This battle was part of the larger struggle for power in southern Italy during the early 12th century when various factions vied for control over the region. Ranulf II had the support of several local nobles, while Roger II brought together a powerful contingent of Sicilian knights and soldiers. The location of Nocera was strategically important, situated near Salerno, which had been a focal point for regional conflicts. The clash on the battlefield represented not just a fight for territorial supremacy but also a contest between different visions of governance in medieval Italy.

The battle itself was marked by fierce engagements, with both sides employing tactics of cavalry charges and infantry maneuvers. The outcome was critical; Roger II emerged victorious, which allowed him to further consolidate his power over the southern Italian territories. This victory not only secured Roger's position in the region but also set the stage for the eventual unification of the Kingdom of Sicily. It played a pivotal role in shifting the balance of power and diminishing the influence of local nobility, symbolized by Ranulf II’s defeat.

In the aftermath, Roger II continued his campaigns, which culminated in the establishment of the Kingdom of Sicily, a significant political entity in the Mediterranean. The battle and its outcomes stimulated social and political changes that reshaped the landscape of southern Italy and influenced interactions with other regions, including the Papacy and the Byzantine Empire.