This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Example input: Passage: The French and Indian War (17541763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict.
Example output: When was the French and Indian War?
Example explanation: This question is based on the following sentence in the passage- The French and Indian War (17541763) was the North American theater of the worldwide Seven Years' War. It is a common convention to write (start year-end year) beside a historical event to understand when the event happened. You can ask questions like this one about dates, years, other numerals, persons, locations, noun phrases, verb phrases, adjectives, clauses etc. which exist in the paragraph.
Q: 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. 871899) 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. 936973) 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. 967983) to Theophanu (d. 991), daughter of an earlier Byzantine Emperor Romanos II (r. 959963). By the late 10th century Italy had been drawn into the Ottonian sphere after a period of instability; Otto III (r. 9961002) 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.
A:
When did Alfred the Great begin his reign?