Alboin (d. 572 or 573), king of the Lombards, and conqueror of Italy, succeeded his father Audoin about 565. The Lombards were at that time dwelling in Noricum and Pannonia (the plain of eastern Austria south and east of the Danube, modern-day Slovenia and Istria). In alliance with the Avars, an Asiatic people who had invaded central Europe, Alboin defeated the Lombards' hereditary enemies, the Gepidae, a powerful nation on his eastern frontier, slew their new king Cunimund , whose skull he fashioned into a drinking-cup, and whose daughter Rosamund he carried off and made his wife.

Three years later, in April, 568, on the alleged invitation of Narses, who was irritated by the treatment he had received from the emperor Justin II, Alboin invaded Italy, with the women and children of the tribe and all their possessions, with 20,000 Saxon allies and the subject tribe of the Gepidae and a mixed host of other barbarians, probably marching over the pass of the Predil and crossing the great plain at the head of the Adriatic into Italy. The Gothic War , which had ended in the downfall of the Goths, had exhausted Italy, which was wracked with famine and plague, and the Eastern Emperor's government at Constantinople was powerless to retain the Italian province which Belisarius and Narses had recently recovered for it. Alboin's horde overran Venetia and the wide district which we now call Lombardy, took Milan in 569, meeting with but feeble resistance till he came to the city of Ticinum (Pavia), which for three years (569-572) kept the Lombards at bay and then became the new capital. Where the Lombards did meet with resistance, retribution was savage beyond anything Italy had experienced before. The bishops, who were virtually the leaders of the late antique Roman cities, fled, like the bishop of Milan, or compounded with the barbarians for gentler treatment of their people.

While the siege of Pavia was in progress Alboin was also engaged in other parts of Italy, and at Pavia's capitulation he was probably master of Lombardy, Piedmont and Tuscany, as well as of the regions which afterwards went by the name of the duchies of Spoleto and Benevento.

In 572, according to Paul the Deacon (Paulus Diaconis), the 8th century Lombard chronicler, Alboin fell a victim to the revenge of his wife Rosamund, the daughter of the king of the Gepidae, whose skull Alboin had turned into a drinking cup and wore at his belt, out of which he forced Rosamund to drink. She had him assassinated by his chamberlain Peredeo and fled to the protection of the Byzantine representative at Ravenna.

In these few years the Lombards had established themselves in the north of Italy (henceforth Lombardy). But they had little practice in governing large provinces. Lombard warlords (which Latin chroniclers called 'dukes') were established in all the strongholds and passes, and this arrangement became increasingly characteristic of the Lombard settlement. Their power extended tenuously across the Apennines into Liguria and Tuscany, and southwards to the outlying Lombard dukedoms of Spoleto and Benevento. The invaders failed to secure any maritime ports or any territory that was conveniently commanded from the sea, such as Byzantine Ravenna. Local inhabitants fled into the marshes and lagoons, where Venice had its beginnings.

After his death and the short reign of his successor Cleph the Lombards remained for more than ten years without a king, ruled by the various dukes.

The authorities for the history of Alboin are first of all Paul the Deacon, the Byzantine Procopius, and Agnellus (in his history of the church of Ravenna).