Oromo migrations

According to Bahrey, the earliest Oromo expansion occurred under the Oromo luba Melbah, during the time of Emperor Lebna Dengel. He states that they invaded the neighboring Bale in the Southeast just before the invasions of Ahmad ibn Ibrahim al-Ghazi of Adal (also known as Ahmed Gurey) in the north. These early incursions (Oromo: razzia) were limited, however, as the encroaching groups returned to their homeland near the Shebelle River after each raid. Raids continued under Mudena past the Wabi Shebelle, but these groups also returned home shortly.[2]

After the death of Ahmed Gragn, Kilolé resumed his predecessor's raids, piercing further into Ethiopian territory. Aided by the weakening of both the Ethiopian Empire and Adal, he was able to raid as far as the province of Dewaro, north of Bali. Again, however, after each raid, the parties returned to their villages. Bahrey's dating might, however, be off, however, as Shihab ad-din, who wrote a decade before Ahmed Gragn's death, notes a locality named Werre Qallu, an Oromo name, in the province of Dawaro. Francisco de Almeida, however, agreed with Bahrey's dating, affirming that the Galla first began migrating around the time of Ahmed Gragn's invasion (1527).[3]

Meslé's time represent a fundamental change in the expansion of the Oromo. Not only were newly taken territories permanently settled by Oromo for the first time, but mules and horses began to be ridden by the first time. The adoption of horseback-riding from the north greatly increased the Oromo fighting power, putting them on par with Ethiopian troops, who were largely unequipped with firearms.[6] In the new phase of migration adopted under Meslé, the Oromo defeated Gelawdewos's troops in Jan Amora, allowing them to pillage a number of towns. Instead of returning to their homelands, however, they stayed in the new territories. 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.[5]

Oromo expansions were not restricted to Ethiopian territories, however, as activities against Adal were also pursued. The forces of Nur ibn Mujahid (r. 1551/2–1567/8), the Amir of Harar, for instance, were soundly defeated by the Oromo. According to Bahrey, there had been "no such slaughter since the Galla first invaded."[5]

During the luba of Harmufa rule, the Oromo advanced even deeper into Ethiopian territory. With the use of horses, they were able to attack the province Amhara, and Angot. Further advances were made under Robalé, during whose time Shewa was pillaged and Gojjam attacked. For the first time, Oromo advances were devastating core Ethiopian provinces, whereas there earlier incursions were simply against frontier provinces. Despite the deeper attacks, the core provinces remained under Ethiopian control, and Emperor Sarsa Dengel carried out punitive expedition in return. One such reprisal in 1573 involved the engagement of Oromo near Lake Zway in a frontier province, whom he defeated, and taking their cattle and distributing it among his subjects who are described in his chronicle as "becoming rich" as a result.[7]

At the same time, Barentu Oromo groups attacked Adal Sultanate, which was weakened by its wars with the Abyssinians and Portuguese Empire leading to no potential resistance. Only a few small groups of Muslims were able to flee to Zeila and survive within the fortified city. The greater part of the Muslim population was assimilated by the Oromos.[8]

The city Dire Dawa was originally called Dir Dhabe and used to be part of Adal Sultanate during the medieval times and was exclusively settled by Dir which is a major Somali clan and after the weakening of Adal Sultanate, the Oromos took advantage and were able to penetrate through the city and settle into these areas and also assimilate some of the local Gurgura clan.[9]

The Hawiye and Dir clans used to be the predominant inhabitants of Hararghe Highlands in the medieval times until the weakening of Adal Sultanate the opportunist Oromos took advantage of the crippling state and decided to invade and occupy the Haraghe Highlands and assimilate the local native Somali clan population which were Jarso, Akisho, Gurgura, Nole, Metta, Oborra and Bursuk who were all sub-clans of Dir a major Somali tribe and were later confederated into Oromo tribe, the Afran Qallo clan.[10]

However, some Somalis, namely the Karanle were still strong and were able to successfully resist the Oromo expansion in their territories and hold them off at Babille, Dire Dawa and Mieso.

Despite Sarsa Dengel's military campaigns, the Oromo expansion continued to spread northward during this time. It was under luba Birmajé that the Oromo first began to use body-length ox-hide shields. These shields allowed the Oromo to resist arrows and therefore successfully defeat the Mayas. During this time period, the Oromo often came into conflict with Daharagot, one of Sarsa Dengel's commanders, who was often successful. Nevertheless, during this time, the Oromo pillaged Ar'ine in Wej, killing Ethiopian couriers in the process. Further advances were made around Lake Tana, Dembiya, and (old) Damot, which was surrounded and some of whose inhabitants were enslaved.[12]

Under luba Mul'eta a large raid (Oromo: dulaguto) was made on Gojjam south of Lake Tana. With the Ottoman situation in the north largely under control, Sarsa Dengel again took the initiative against the Oromo in the south, where he forced the Dawé (or Jawé) Oromo in Wej to flight.[12] Bahrey praised Sarsa Dengel's campaign, stating that he "did not act according to the custom of the kings his ancestors, who, when making war were in the habit of sending their troops ahead, remaining themselves in the rear with the pick of their cavalry and infantry, praising those who went forward bravely and punishing those who lagged behind."[13] Despite Bahrey's praise, Sarsa Dengel was forced to use coercion to draw troops, announced decree that anyone who failed to heed his call to arms would have his house pillaged and property confiscated.[14]