Arechis II of Benevento transferred the seat of the Duchy of Benevento to Salerno, in order to elude Charlemagne's offensive and to secure for himself the control of a strategic area, the centre of coastal and internal communications in Campania.
With Arechis II, Salerno became a centre of studies with its famous Medical School. The Lombard prince ordered the city to be fortified; the Castle on the Bonadies mountain had already been built with walls and towers. In 839 Salerno declared independence from Benevento, becoming the capital of a flourishing principality stretching out to Capua, northern Calabria and Puglia up to Taranto.
Around the year 1000 prince Guaimar IV annexed Amalfi, Sorrento, Gaeta and the whole duchy of Puglia and Calabria, starting to conceive a future unification of the whole southern Italy under Salerno's arms. The coins minted in the city circulated in all the Mediterranean, with the Opulenta Salernum wording to certify its richness.
However, the stability of the Principate was continually shaken by the Saracen attacks and, most of all, by internal struggles. In 1056, one of the numerous plots led to the fall of Guaimar. His weaker son Gisulf II succeeded him, but the begin of the decline for the principality had begun. In 1077 Salerno reached its zenith but soon lost all its territory to the Normans.
Salerno under the Normans, Hohenstaufen and Anjou
On December 13, 1076 the Norman conqueror Robert Guiscard, who had married Guaimar IV's daughter Sichelgaita, besieged Salerno and defeated his brother-in-law Gisulf. This act put an end to hundreds of years of Lombard dominance, but did not check the city's vitality. In this period the royal palace (Castel Terracena) and the magnificent Arab-Gothic style cathedral were built, and science was boosted as the Salerno Medical School, considered the most ancient medical institution of European West, reached its maximum splendour.
Salerno played a
