Aiulf I was the duke of Benevento from 641 to his death in 646 as the son and successor of Arechis I

Arechis I of Benevento

Arechis I was the second duke of Benevento from 591 to his death in 641, a reign of half a century. He was from Friuli and was a relative of the dukes there, maybe a nephew of Zotto, his predecessor. He was appointed by King Agilulf in the spring of 591, after Zotto's death...

. However, he was mentally unstable and his adoptive brothers Radoald

Radoald of Benevento

Radoald was the duke of Benevento from 646 to his death in 651. His elder brother, Aiulf was mentally unstable and Radoald and their younger brother Grimoald were regents. Radoald and Grimoald were brothers as younger sons of Gisulf II of Friuli...

 and Grimoald

Grimoald I of Benevento

Grimoald I was duke of Benevento and king of the Lombards .Born probably before 610 to Duke Gisulf II of Friuli and the Bavarian princess Ramhilde, daughter of Duke Garibald I of Bavaria, he succeeded his brother Radoald as duke of Benevento...

 were regent

Regent

A regent, from the Latin regens "one who reigns", is a person selected to act as head of state because the ruler is a minor, not present, or debilitated. Currently there are only two ruling Regencies in the world, sovereign Liechtenstein and the Malaysian constitutive state of Terengganu...

s for him. In 646, Slavic plunderers landed near Siponto

Siponto

Siponto was an ancient port town of Apulia in southern Italy. The town was abandoned after earthquakes in the 13th century; today the area is administered as a frazione of the comune of Manfredonia, in the province of Foggia...

 on the Adriatic. Aiulf personally led his forces against the intruders, but his horse fell into a pit dug by the Slavs around their camp and he was surrounded and killed. He was succeeded by his brother Radoald.