Tafari moved calmly towards supreme power, stepping cautiously and never risking a wrong step or another that might endanger him. He progressed from 'Lij' prince, then commander of the 'Djaz' region, then to commander of the 'Ras' army; and finally, on October 27, 1928, the Empress crowned him 'Negus' (King) through the Church, and he thus became the sole 'Negus' in the empire, a royal title that was not granted to anyone else throughout his reign. Thus, the Church was harnessed, and the Empress became merely a symbol.

Up to that moment, Tafari had managed to quell numerous rebellions and insurrections. In 1928, a number of military leaders resented the stripping of the Crown Prince Empress of her powers and began a movement led by Dajach Balchasamo, governor of the Sidamo province, accusing Tafari of selling the country, referring to the privileges he granted to foreigners. However, their movement failed, they were arrested and imprisoned, and their property was confiscated. Dajach Abawikao Biru, commander of the Imperial Guard, also challenged Tafari and showed loyalty to the Empress, but Tafari managed to quell his rebellion as well. In the month of his coronation, a major rebellion occurred in the 'Wallo' region and spread to all areas of the Oromo, who demanded the return of Prince Iyasu, if he was still alive or his fate known. However, the rebellion of Ras Gugsa was the most dangerous; he was the former husband of the Empress, and he held Tafari responsible for his separation from his wife. He had a large fief in the Qandara province, which Tafari began to covet for distribution to his supporters. The control of customs revenue from the Alamat border post with Sudan added another factor to the conflict.

It is said that the Italians in Eritrea incited Gugsa to rebellion and disobedience, as did the governors of Gojam, Ras Hailu Tekle Haimanot, and Tigray, Ras Seyum Mengesha. Despite the Empress's pleas to her former husband, a clash was inevitable by the end of 1930, where warplanes were used for the first time to crush the rebellion in which Gugsa was killed. Two days later, the Empress died, and Tafari was crowned Emperor and 'King of Kings', choosing the name Haile Selassie, meaning the power of the Holy Trinity, in November 2, 1930. The coronation ceremony was unparalleled in Ethiopia and the region in terms of luxury, extravagance, and splendor. Festival and celebration organizers from Europe were used for the ceremony, and the official imperial carriage of Germany was brought to transport the royal couple. Gold and velvet were everywhere, and a massive campaign was launched to beautify the capital, Addis Ababa. Slums were removed from the main roads, royal palaces were illuminated, important roads were paved, and even the police wore new uniforms.