The siege of Salerno was one of the campaigns of the Aghlabids in southern Italy during their conquest of Sicily. The Lombard city of Salerno had strong defences and, despite the use of stone-throwing artillery, the siege lasted a little over a year from its beginning in late 871 or early 872. Prince Guaifer of Salerno led the defence, but the siege was only lifted by the arrival of an army of Lombards and Franks under the Emperor Louis II.
Background
Louis II, King of the Lombards and Emperor of the Romans, fought a five-year campaign against the Emirate of Bari, which fell in February 871. In August, Louis was betrayed and imprisoned by Prince Adelchis of Benevento. He was freed a month later on the condition that he not return. He was in northern Italy when the Aghlabid army invaded southern Italy a few months later. On 17 May 872, in Rome, he obtained from Pope Adrian II the nullification of his oath to Adelchis. He then placed the prince under the ban of the Empire.
The conquest of Calabria and assault on Salerno, the most important city in Campania, was the Aghlabid response to the fall of Bari. The Aghlabid emir Muḥammad II appointed one ʿAbd Allāh as wālī (governor) of al-Arḍ al-Kabīra (the Big Land, i.e., the Italian peninsula). At the same time, ʿAbd Allāh's brother Ribbāh was appointed wālī of Sicily, since the previous wālī, Muḥammad ibn Khafāja, had died early in 871. Abd Allāh and Ribbāh were the sons of Yaʿqūb ibn Fazāra and relatives of al-ʿAbbās ibn al-Faḍl, who was the governor of Sicily from 851 to 861, known for encouraging settlement in Calabria and Apulia.
Sources
The main Latin sources are the contemporary historians Erchempert and Andreas of Bergamo and the Chronicon Salernitanum, written about 980. The Vita et translatio sancti Athanasii neapolitani episcopi, a biography of the bishop of Naples, is a source for the embassy that preceded the attack.
Among Arabic accounts, the Bayān of Ibn ʿIdhārī writes suggestively of ʿAbd Allāh's victories, but does not describe the end of the campaign. The Tarʾīkh Jazīrat Ṣiqilliya, on the other hand, describes the Arabs' defeat, putting it in the Byzantine year 6380, corresponding to 871–872.
The Greek De administrando imperio gives a wholly "mythical" and "apocryphal" account of the siege of Salerno.
Advanced warning and preparations
The Salernitans had advanced knowledge of the attack, which allowed them to make preparations and gather allies. According to the account in the Chronicon Salernitanum, forewarning of the attack came from an Amalfitan merchant, who had been entrusted with the message while staying Ifrīqiya by an Arab who had been the recipient of Prince Guaifer's generosity. On a previous visit to Salerno, this Arab had complimented the prince on his cap while the latter was passing through the forum on his way to the palace from the public baths, whereupon the prince gave the Arab his cap. If any credence can be given to this story, Guaifer's exchange with the Arab must have taken place in the spring of 871, shortly after fall of Bari.
In preparation for the siege, the city's defences were strengthened and the garrison reinforced. Troops came from the Lombard principalities of Benevento and Capua. Guaifer dispatched an embassy to northern Italy to ask the Emperor Louis II for aid. The importance attached to this embassy can be gauged from the prestige of the envoys: Guaifer's son and heir, the future Prince Guaimar I; Bishop Landulf II of Capua; Bishop Athanasius II of Naples; and representatives from Pope Adrian II. This embassy took place between September and November 871. Louis initially rejected its entreaties and even imprisoned Guaimar for a time. Even Adelchis may have sought help from Louis—if the theory linking the composition of the poem De captivitate Ludovici imperatoris with the siege of Salerno is correct.
Campaign
The Aghlabid force under ʿAbd Allāh crossed from Ifrīqiya, landed in Calabria and marched overland to Salerno, according to the Chronicon Salernitanum. Andreas of Bergamo, on the other hand, has them landing at Taranto. The Chronicon Salernitanum pegs the force at 72,000. Erchempert puts it at 30,000. Both numbers are exaggerations, but they do indicate that the Aghlabid army was considered very large. During its march north, it captured "many towns", in the words of Erchempert. It forced the Frankish army that was besieging Taranto, where the last remnants of the emirate of Bari were holding out, to abandon the siege.