Grimoald IV son of Ermenrih, called Falco, was the Lombard

Lombards

The Lombards , also referred to as Longobards, were a Germanic tribe of Scandinavian origin, who from 568 to 774 ruled a Kingdom in Italy...

 Prince of Benevento from 806 until his death. He was a thesaurarius or stolesayz/stoleseyz before becoming prince on the death of Grimoald III

Grimoald III of Benevento

Grimoald III was the Lombard Prince of Benevento from 788 until his own death. He was the second son of Arechis II and Adelperga. In 787, he and his elder brother Romoald were sent as hostages to Charlemagne who had descended the Italian peninsula as far as Salerno to receive the submission of...

, over Grimoald's own son, Ilderic, another stoleseyz.

In 812, he was forced to pay 25,000 solidi in tribute to Charlemagne

Charlemagne

Charlemagne was King of the Franks from 768 and Emperor of the Romans from 800 to his death in 814. He expanded the Frankish kingdom into an empire that incorporated much of Western and Central Europe. During his reign, he conquered Italy and was crowned by Pope Leo III on 25 December 800...

. In 814, he pledged an annual tribute of 7,000 solidi to Louis the Pious

Louis the Pious

Louis the Pious , also called the Fair, and the Debonaire, was the King of Aquitaine from 781. He was also King of the Franks and co-Emperor with his father, Charlemagne, from 813...

. These promises, however, were never kept and his successor, Sico

Sico of Benevento

Sico was the Lombard Prince of Benevento from the 817 to his own death.-Life:Before becoming the Prince of Benevento, he had been the gastald of Acerenza. On the assassination of Grimoald IV, Sico succeeded to the princely throne...

, made the same empty guarantees. The Beneventans were independent in practice and by the end of the ninth century would not even recognise Frankish overlordship. Grimoald was assassinated in 817 by a complot of nobles vying for his throne.