According to the historian Merid Wolde Aregay they were originally Christians but many were converted to Islam by Ahmad Gran and assisted him in his conquest of the province of Bete Amhara.

Due to their native origin, the yejju mostly spoke Amharic and adapted themselves better than the rest of the Oromo clans in Wollo to the traditional social and political structures of Christian Ethiopia.

One theory is that the Yejju are the results of various layers of people: the Amhara population of Angot, remnants of the forces of Ahmad Gragn, and the migrating Oromo.

[11] This tradition states Yejju claim origin from the sixteenth century scholar Umar who had settled in the region during the Adalite occupation of Ethiopia.

Many Oromos did not seem to care about jockeying for power but had been in a competition for land against the Tigrayans to the north of them so they complied 20,000 well-armed cavalry to assist the Amhara against the enemy.

[14][15] Their support was decisive and Amhara nobles sent an invitation and a plea for the fighting force to stay in Gondar to defend the Negus and to act as a deterrent to future threats from Tigray.

A Scottish traveller, James Bruce, who visited Gonder during the period under discussion, wrote that "Nothing was heard at the palace but the Afaan Oromo language".

It was Mentewab, the wife of Bakaffa, who arranged marriage alliance between her son Iyasu II and a Muslim Oromo princess from Wollo, Wabi, the daughter of Amito, a powerful Wolloye chief.

This dynastic marriage alliance had remarkable importance for the Oromo lords of Wollo in gaining further access to the royal court and dominating the Empire since the 1780s.

The founder of this new dynasty of the Oromo regents was Ras Ali I of Yejju, who ruled the province of Begamder and Amhara from his centre in Debra Tabor.

Sabagadis attempted to gain a foothold on the coast of the Red Sea for the British monarch to take so that he may breach the wall of isolation around Ethiopia and create a bridge to Christian Europe.

Although the Tigrayans had a superior army, due to the equipment by the British, the match-locked men were poorly employed and the Oromo cavalry won the field after a most bloody fight in which the Ras was killed.

The people of this country, will they find it a good thing To eat ears of corn which have grown in the blood Who will remember St. Micheal of November to give alms?

Mariam (Marye), with five thousand Gallas, had killed him For half of a loaf, for cup of wine, The friend of the Christians has fallen at Daga Shaha.

The growing tension in Dembya and Wogera had grown due to rebellious shifta leaders, specifically Kassa Hailu who were defying her authority.

Ras Ali II who escaped after his defeat with his followers returned to Debra Tabor and grudgingly rewarded the true victor, Aligaz, with the governorship of Daunt, a district to the south of Amhara bordering the Wollo country while Merso was given all of Wube's territories.

In such conditions, Ali found himself in dire need of the Abyna's support, leading him to be open to Abuna Salam's counsel to free Wube and restore his properties to him in exchange for minimal recompense and a pledge of loyalty.

Dejazmatch Merso, who had reached Semien in the meantime, refused to give his brother's governorship, and the Ras was forced to march with his former enemy against his loyal ally.

In October 1841, the missionary Krapf who was in Shewa wrote the following: If Muhammad Ali will capture Abyssinia he would be able to recruit forces for the army, especially by taking and organizing... the Galla people, who will furnish him with men and horses.

However, when the Belgian Consul in Egypt arrived in Gondar to negotiate with the Ras, a messenger of Muhammad came to him carrying the following message signed with the seal of the Pasha:Do not fear, your friends will be my friends and your enemies will be my enemies.His words did not match his actions as later Muhammad Ali would dispatch the Egyptian army to Wehni to take advantage of the Ethiopians who were in a difficult situation with internal matters.

Although Wube at this point had given up his imperial aspirations of restoring the Solomonic dynasty, he had continued adopted the policy of fostering relations with the European Powers from former governor of Tigray, Sebagadis.

One of the Shifta leaders, Kassa Hailu who was a relative to Dejazmatch Kinfu, had gained the support of the local populace and rose to much fame that the Ras and Mennen wanted him on their side.

During April 1846, Ras Ali, who was preparing for his annual expedition against Aligaz Goshu, called upon his tributary Dejazmatch Wube to send him funds and soldiers his coming campaign.

Rebellions broke out different provinces, Balgada Araya, an enemy of Wube, declared himself ruler of Tigray, and Muhammad Ali had assumed full authority on the coast of the Red Sea.

Taking advantage of this situation, Dejazmatch Goshi and his son Birru Goshu invaded Begamder and finally reached Gondar at the end of the year.

Between the years 1849 and 1852 most of northern Ethiopia enjoyed a period of relative stability and internal peace, the like of which it had not known since the times of Ras Gugsa, but this was just a lull before the big storm which was to bring the Zemene Mesafint to an end and change the history of the country.

The battle shocked the entire country and Kassa was finally able to come from behind his mask of submissiveness and openly declare his aim to defeat Ali and reunite Ethiopia under his rule.

A short time after the battle of Taqusa, Kassa marched his army southwards to Debra Tabor, but in the meantime the Ras had moved down to the plains of Ayshal, which were particularly suitable for the employment of his unbeatable Oromo cavalry.

After the burning of Debra Tabor, Kassa followed Ras Ali to Qwarta and on the 29th of June, the two armies clashed at Ayshal in one of the bloodiest battles of the Zemene Mesafint.

Accounts of Haile Selassie's journey from Addis Ababa in 1936 indicate that the Wollo Oromo spat at him and he passed through their areas he refused to travel there again (Shepherd 1975:9).With the adoption of ethnic federalism in 1994 and the abolishment of the Awrajja administrative structure, Yejju was divided between the districts of Habru, Weldiya town, and the mid-altitude portion of Guba Lafto.