The Lombards of the principalities of Salerno and Benevento alternated alliances and oppositions with the raiding nomads of north Africa (so called "Saracens") who had meanwhile occupied the fortress of Agropoli, Taranto and Bari and nevertheless the Opulent Civitas of Salerno was teeming with resident people and guests of opposing ethnic groups and cultures.

The Chronicon Salernitanum, datable to the year 871, tells of a chance meeting between the Saracen merchant Arrane and Prince Guaiferio. On a sunny summer afternoon in the city of Salerno a Saracen that circulated in the streets meets Guaiferio who was returning from the beach of Santa Teresa after a refreshing bath with a towel over his head to shelter, Arrane, this was the name of the Arab, not recognizing the prince in the interlocutor having mistaken him for a simple Arimanno, he asked him for a handkerchief to wipe away the sweat he was soaked in, surprised and amused Guaiferio took off the cloth and gave it to the stranger, the Saracen praised the gesture of the Prince who meanwhile had resumed his path and only after following him with his eyes did a passer-by reveal the status of the knight.

A few days after Arrane left Salerno to return to Africa (Ifrîqiya), he landed in Algiers, in his eyes the excessive crowding of ships and warriors on the streets of the city immediately stood out: he began to ask the reason for that extraordinary movement and, in acknowledging that the emir Adb-Allah was arming a mighty fleet and at the same time he was enlisting a strong army to invade the Italian coasts and kill the city of Salerno, dismayed the Saracen quickly considered to warn the Lombard prince of the next danger, in his mind there it was the quick confrontation between the arrogant ways of the Muslim leaders against the kindness and simplicity of the ways of Guaiferio.

He therefore worked to learn more about the details of the undertaking underway by writing them down in a letter with indications on the likely directions of the attack and recommending strengthening the defensive structures for the city.

Then, using the merchants' network, he entrusted the whole package to an Amalfitan named Florio leaving for Salerno with the prayer to have it reach the direct hands of the prince and with the recommendation to prelude the delivery with the phrase "These words you lets you know the Arab to which you donated the handkerchief ”, so that Guaiferio could quickly run for cover by strengthening the fortifications of the city.

A siege of great proportions, led by the Saracen leader Abd Allâh, actually began in September of the same year, ending with the liberation of the city in August of the following year thanks to the decisive intervention of Ludwig II.

The scene of the meeting between Guaiferio and Arrane is indicative, in addition to the existence of a square used as a market, of a recurring presence in the city of Saracen merchants (and also from Amalfi, since the person approached by Arrane in Africa declared often entertain himself with the prince of Salerno) and at the same time of a certain importance of the commercial relations between the city and the Berber area of ​​North Africa, since the merchant seems to be very concerned about the probable collapse of Salerno under the siege of his compatriots, and he prefers to betray his own people rather than risk seeing his trafficking interrupted.

If any credence can be given to this story, Guaifer's exchange with Arrane must have taken place in the spring of 871, shortly after fall of Bari. The episode of the merchant Arrane can be useful not only because it is the only irrefutable foothold to support a link between Salerno and Arab trade in the 9th century, but also because the will to organize a massive military attack directed at the city of Salerno in Africa meant know well the richness and prosperity of the products.