What is "ubba"

Ubba, also known as Hubba, Ubbe, and Ubbi, was a mid-ninth-century Viking chieftain and one of the commanders of the Great Army, a coalition of Norse warriors that in AD 865 invaded the Anglo-Saxon kingdoms of Northumbria, Mercia, East Anglia and Wessex.

Contemporary English sources tend to describe the army's men as Danes and heathens, but there is evidence to suggest that a proportion of the force originated in Frisia, and one source describes Ubba as dux of the Frisians. In 865 the Great Army, apparently led by a man named Ivar, overwintered in East Anglia, before invading and destroying the kingdom of Northumbria. In 869, having been bought off by the Mercians, the Vikings conquered the East Angles, and in the process killed their king, Edmund, who was later regarded as a saint and martyr. While near-contemporary sources do not associate Ubba with the latter campaign, some later, less reliable sources associate him with the king's martyrdom. Others associate Ubba and Edmund's martyrdom in traditions concerning the saga-character Ragnar Lothbrok.

After the fall of the East Anglian kingdom, leadership of the Great Army appears to have fallen to Halfdan, Ivar's brother. The Vikings then campaigned against the West Saxons and destroyed the kingdom of the Mercians. In 873 the Great Army split in two: Halfdan led one part to campaign in the north before settling in Northumbria; the other part, under a leader named Guthrum, campaigned against the West Saxons. In the winter of 877–78 Guthrum launched a lightning attack deep into Wessex, which may have been coordinated with a separate Viking force campaigning in Devon. According to a near-contemporary source, this force was led by a brother of Ivar and Halfdan, and some later sources identify him as Ubba.