On April 3, 1941, the last war council of the Royal Army met in Ghebi, the seat of the colonial government, in Addis Ababa. Viceroy Amedeo d'Aosta proposed creating a fortified post on Amba Alagi to continue the resistance, as it was considered a natural fortress. Amedeo left the following day with 7,000 men to mount a desperate resistance.

Amadeo of Savoy, third Duke of Aosta, became Viceroy of Ethiopia at the end of 1937, replacing Rodolfo Graziani. Graziani's policies were characterised by violence; Amedeo, meanwhile, sought to implement policies more sympathetic to the indigenous populations. Military tribunals were abolished, and several political prisoners were freed. The pacification of Ethiopia was sought through the power of local nobles rather than through violence. Historian Paolo Borruso defines all these actions as "indigenous policies," praising Amedeo as a colonial governor.

In June 1940, Amedeo became Supreme Commander in Italian East Africa, which included Eritrea, Somalia, and Ethiopia. The first military operations achieved successes against the British in Kassala and British Somaliland, but these manoeuvres exhausted the troops and depleted the colonies' few war resources. The difference was made by the British navy and air force, as well as their armoured vehicles, which secured decisive victories. After the fierce, month-long Battle of Keren, Italian positions suffered a violent collapse throughout the territory, forcing the viceroy to propose a last-ditch stand on Amba Alagi.

At the end of April, the positions protecting the entrances to the mountain fell to British artillery fire. The first week of May, as Amedeo recounts in his diary, was particularly difficult due to the constant bombardment and the cold nights. As the days passed, food and water rationing began, lowering the troops' morale; But the real problem was the issue of the wounded, as there was no way to adequately care for them, as Amedeo wrote on May 15th, "I cannot keep the wounded under cannon fire; today too was hell." On May 19th, the Italians surrendered, with the British Army granting the honours of war to the Royal Army.

The veterans of the Alagi were taken prisoner and taken to various camps. The viceroy was interned in Donyo Sabouk, Kenya, where he died the following year from a lung infection.