Redbad II (rule 760–786 or 734–754 or 749–775) was a possible king of Frisia. He was the son of Adgillis III. His territory was east of the Lauwers

Lauwers

The Lauwers is a river in the Netherlands. It forms part of the border between the provinces of Friesland and Groningen. From the 730's to Widukind's defeat in 785 it was part of the border of the Frankish Empire....

 and included present day East Friesland and Groningen

Groningen (province)

Groningen [] is the northeasternmost province of the Netherlands. In the east it borders the German state of Niedersachsen , in the south Drenthe, in the west Friesland and in the north the Wadden Sea...

, the last now being part of the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

.

At this time Frisia had already been conquered by the Franks

Franks

The Franks were a confederation of Germanic tribes first attested in the third century AD as living north and east of the Lower Rhine River. From the third to fifth centuries some Franks raided Roman territory while other Franks joined the Roman troops in Gaul. Only the Salian Franks formed a...

, and in 775, 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...

  made Frisia officially part of the Frankish Realm.

The different dates are derived from different sources. Hamconius is one source, the Oera Linda

Oera Linda

The Oera Linda Book is a 19th century manuscript written in Old Frisian. It purports to cover historical, mythological, and religious themes of remote antiquity, compiled between 2194 BC and AD 803....

is a fraudulent book also mentioning him