Battle of Debre Tabor: Ras Ali Alula, Regent of the Emperor of Ethiopia defeats warlord Wube Haile Maryam of Semien.

The Battle of Debre Tabor was a conflict during the Zemene Mesafint in 1842 initiated by Dejazmach Wube Haile Maryam to overthrow Ras Ali II as Regent of the Emperor of Ethiopia and gain control of Ethiopia. This confused battle was won by Ras Ali, but at a steep price, and this victory failed to cement his position as the most powerful nobleman of his time.

Ali II of Yejju was Ras of Begemder and the de facto ruler of the Ethiopian Empire. He was a member of a powerful Wollo Yejju dynasty known as the Yejju, which ruled much of the Ethiopian Empire during the Zemene Mesafint.

The emperor of Ethiopia, also known as the Atse, was the hereditary ruler of the Ethiopian Empire, from at least the 13th century until the abolition of the monarchy in 1975. The emperor was the head of state and head of government, with ultimate executive, judicial and legislative power in that country. A National Geographic article from 1965 called Imperial Ethiopia "nominally a constitutional monarchy; in fact it was a benevolent autocracy".

Wube Haile Maryam of Semien,, also called by his title Dejazmach Wube, Webé; his name is also given in European sources as ‘‘Ubie’’, was one of the major figures of 19th century Ethiopia, during the closing decades of the Zemene Mesafint a period of regional lords vying for power, prestige and territory amid a weakened authority of the emperors.