Ethiopia in roughly its current form began under the reign of Menelik II, who was Emperor from 1889 until his death in 1913. From his base in the central province of Shewa, Menelik set out to annex territories to the south, east and west, areas inhabited by the Oromo, Sidama, Gurage, Welayta, and other peoples. He did this with the help of "Ras" Gobana Dacche's Shewan Oromo militia, which occupied lands that had not been held since Ahmad ibn Ibrahim al-Ghazi's war, as well as other areas that had never been under Ethiopian sovereignty. During the conquest of the Oromo, the Ethiopian Army carried mass atrocities against the Oromo population including mass mutilation, mass killings and large-scale slavery. Some estimates for the number of people killed as a result of the conquest go into the millions. Large-scale atrocities were also committed against the Dizi people and the people of the Kaficho kingdom. Menelik's campaign against Oromos outside his army was largely in retaliation for centuries of Oromo expansionism and the "Zemene Mesafint", a period during which a succession of Oromo feudal rulers dominated the highlanders. Chief among these was the Yejju dynasty, which included Aligaz of Yejju and his brother Ali I of Yejju. Ali I founded the town of Debre Tabor in the Amhara Region, which became the dynasty's capital.