Read this: Efforts by local kings to fight the invaders led to the formation of new political entities. In Anglo-Saxon England, King Alfred the Great (r. 871–899) came to an agreement with the Viking invaders in the late 9th century, resulting in Danish settlements in Northumbria, Mercia, and parts of East Anglia. By the middle of the 10th century, Alfred's successors had conquered Northumbria, and restored English control over most of the southern part of Great Britain. In northern Britain, Kenneth MacAlpin (d. c. 860) united the Picts and the Scots into the Kingdom of Alba. In the early 10th century, the Ottonian dynasty had established itself in Germany, and was engaged in driving back the Magyars. Its efforts culminated in the coronation in 962 of Otto I (r. 936–973) as Holy Roman Emperor. In 972, he secured recognition of his title by the Byzantine Empire, which he sealed with the marriage of his son Otto II (r. 967–983) to Theophanu (d. 991), daughter of an earlier Byzantine Emperor Romanos II (r. 959–963). By the late 10th century Italy had been drawn into the Ottonian sphere after a period of instability; Otto III (r. 996–1002) spent much of his later reign in the kingdom. The western Frankish kingdom was more fragmented, and although kings remained nominally in charge, much of the political power devolved to the local lords.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Of what dynasty was Otto I a member?
Ottonian dynasty