Sahle Dengel was largely a figurehead, with real power in the hands of the Enderase or Regent, RasAli II a member of the Oromoruling family of the district of Yejju. Eduard Rüppell, who visited the capital of Gondar in 1833, stated that at the time the Emperor "barely had the income of an averagely well-to-do Ethiopian, and the great princes of the Tigray, Shoa and Amhara were unable to prevent continuous strife and bloodshed." When Sahle Dengel was set on the throne by Ras Ali, the clergy of Azazo disapproved of his religious beliefs, and convinced Ras Ali to remove him; Sahle Dengel was sent to Zengaj. Ras Ali recalled Gebre Krestos from Mitraha, an island in northeastern Lake Tana, and restored him as Emperor. However, Gebre Krestos died after three months, and Sahle Dengel met Ras Ali in a village named Tagur, where he convinced the Ras to make him Emperor once again. About that same time, one Egwale Anbesa announced his claim to the throne; Sahle Dengel cut his head off, and set it in a tree at Adababay. Following the death of Ras Kinfu, people fought for control of his lands in Gojjam. Eventually Menen Liben Amede gained the upper hand in the Battle of Chenti Ber, defeating and capturing Kinfu's relative Walda Tekle. Not long afterwards, she deposed Sahle Dengel on 29 August 1840 in favor of her husband Yohannes III. However Yohannes offended Ras Ali by favoring his rival Wube Haile Maryam, and Ras Ali restored Sahle Dengel in October 1841. Sahle Dengel was still emperor in 1848, when Goshu Zewde entered Gondar and was invested with the title of Ras. Yohannes somehow managed to get himself restored to the throne around 1850, only to be deposed again in 1851 and Sahle Dengel was once again restored. Despite this, Yohannes III persisted with his claim; different parts of the fragmented realm recognized one or the other as Emperor until Tewodros II consolidated Ethiopia under his control and declared himself Emperor. Significantly, Yohannes III accepted the accession of Tewodros II.
International relations
Although without power, Sahle Dengel wrote to officials outside Ethiopia using his title and seal. Existing letters include a packet of letters sent to Samuel Gobat in April 1848, who had by that time become the Anglican Bishop of Jerusalem, which ask for his help in restoring the ownership of the Dar-es-Sultan monastery to the Ethiopian community. His name also appears as one of several signatories to a letter Antoine d'Abbadie delivered to Viscount Henry Palmerston18 May 1839, which asked that Queen Victoria ask the ruler of Egypt, Muhammad Ali, to recall his forces which were then ravaging Ethiopia and threatening Gondar.