[1] Over the centuries due to many factors, mostly the wars between the Adal Sultanate and the Ethiopian Empire would further encourage the numerous Oromo tribes to expand towards central and eastern modern Ethiopia.

It is meant to embody "hunger", and the story represents how a powerful entity will consume all there is around it until the "land of plenty" (in reference to the Borana homeland) is left barren and empty.

The legend is interpreted by Mohammed Hassen to be the embodiment of the Christian kingdom's growing power and influence in the regions directly north of the Oromo homelands.

[9] By the 1530s, the Oromo pastoralists had developed a three-staged method for territorial expansion; "scouting, night time surprise attack and settlement" (159).

Once the community under siege was broken down enough to be settled without resistance, the remaining peoples would quickly be integrated through Moggaasaa, having their status, material goods and general livelihoods returned to them.

Francisco de Almeida, however, agreed with Bahrey's dating, by affirming that the Oromo first began migrating around the time of Ahmed Gragn's invasion (1527).

The adoption of horseback riding from the north greatly increased the Oromo fighting power and put them on par with Ethiopian troops, who were largely equipped with firearms.

[15] In the new phase of migration adopted under Meslé, the Oromo defeated Emperor Gelawdewos's Jan Amora corps, allowing them to pillage a number of towns.

Gelawdewos campaigned against the Oromo as a result, defeating them at 'Asa Zeneb (yet unidentified), but he was nevertheless unable to drive them from the frontier provinces and continued to build the new town in Wej for new refugees.

The forces of Nur ibn Mujahid (r. 1551/2–1567/8), the Amir of Harar, for instance, were soundly defeated by the Oromo in an ambush at the Battle of Hazalo.

Despite the deeper attacks, the core provinces remained under Ethiopian control, and Emperor Sarsa Dengel carried out punitive expeditions in return.

[16] At the same time, Barento Oromo groups attacked the Adal Sultanate, which was greatly weakened by its wars with the Christian Ethiopians leading to no potential resistance.

[19] According to Harari chronicles the combination of the Oromo invasion which followed drought led to the destruction of several towns and regions including Sim, Shewa, Negeb, Hargaya and Dakkar.

[25] Its presumed the last remaining pre Oromo invasion inhabitants the Harla people were able to survive due to the fortification of the city of Harar.

[27] According to historian Mohammed Hassen and others, the Oromo invasions were devastating for the Harari people and is one of the major reasons for their diminished populace.

The Oromos took advantage of the crippling state and decided to also invade and to occupy the Hararghe Highlands and assimilate with Somali clan population of Jarso, Akisho, Gurgura, Nole, Metta, Oborra, and Bursuk.

[32] Forced to fight the Ottomans in the north of his empire, Sarsa Dengel turned to curb the spread of the Oromo in the south in the 1570s.

The first mention of his actions is in his short Royal Chronicle, which states that he fought a force of Borana Oromo at Lake Zway under a luba named Ambissa.

[16] Despite the small size of his army, he was able to defeat the Oromo in the area, push them back to Fatagar, and capture a large number of cattle.

Sarsa Dengel was again forced to head north with his army to crush the Ottoman-backed Bahr Negus Yeshaq, but later returned to Wej in 1577–1578 to fend off Oromo advances in the area.

[33] As a result of the battle in the Mojjo Valley (just east of modern Addis Ababa) against the Borana Oromo, corpses were strewn all over the surrounding countryside.

Further advances were then made in Damot, which was situated south of the Blue Nile, according to Bahrey the Boran clan surrounded the province "enslaved the men and carried off the livestock".

A section of the Wollo Oromo raided the Muslim region of Aussa where they defeated and killed Muhammad Gasa, a descendant of Ahmad Gragn.

When this book was written it was the seventh year [i.e. 1593] of the government of Mulata.During the first half of the 17th century, invasions by different Oromo groups were a permanent menace to the Ethiopian Empire.

The ambitious Oromo individuals at his court harnessed the popular fury to their own advantage by overthrowing the king and taking over the kingdom.

The mountainous jungle terrain made rapid cavalry attack and retreat virtually impossible, and their advance was halted by the Kafficho.