Bivin of Frisia (750-) was Duke of Frisia from 768 AD. Bivin was installed as ruler of Frisia by the Westphalian Saxons following their sack of Utrecht; the Saxons aided Bivin in his seizure of power in Frisia, but Bivin disappointed the Saxons by making peace with the Frankish ruler Charlemagne rather than advance on the Frankish city of Ghent. This forced the Saxons to advance on Ghent themselves, resulting in the Battle of Ghent, which destroyed the Westphalian army and enabled the Franks to prepare a counterattack against Frisia.