Discontent with territory and religious dominance led to intense war between the Ethiopian Empire, the Christian state, (consisting of the Amhara, Tigrayan, Soddo Gurage, and Agaw ethnic groups) and the Muslim state Adal Sultanate (consisting of Semitic speaking Harari formally known as the Harla people, and the Argobba).

In the late 19th-century during the reign of Menelik II, against the backdrop of the Scramble for Africa, the notion of Ethiopian national integrity was strengthened by Italian efforts at colonization.

The resulting Treaty of Addis Ababa ended the Italo-Ethiopian War, and along with the nation's contemporaneous territorial expansion, largely established the modern-day boundaries of Ethiopia.

Archaeologist found remains of early hominins, one of the most specimen was Australopithecus afarensis, also called "Lucy", which was discovered in the country's Awash Valley, so-called Hadar in 1974.

In October 2015, scientists discovered the remains of a man called "Mota" in a cave in south-central Ethiopia, he lived 4,500 years ago.

Atypical of Euroasians, who were believed to have reached the region after him, Mota's genetic variants did not include traits such as "light-colored eyes or skin," resembling the modern Aari tribes that live in the southern area of the country.

[19] In 1933, G.W.B Huntingford proposed a theory of Azanian civilization could existed in Kenya, and northern Tanzania, between the Stone Age and Islamic period.

It was supposed that these people evicted from Ethiopia and Somalia by Muslim invasion to southern region in present-day Kenya and Tanzania where perished around 14th- and 15th-century.

[24] Other scholars regard Dʿmt as the result of a union of Afroasiatic-speaking cultures of the Cushitic and Semitic branches; namely, local Agaw peoples and Sabaeans from Southern Arabia.

The kingdom dominated the Red Sea, the Northeast Africa in the present location between northern Ethiopia (Tigray Region), eastern Sudan, Eritrea, South Arabia.

The Aksumite lingua franca was Greek evolved from Hellenistic period in 330–305 BC[citation needed] and officially adopted in the first century.

Politically and culturally influenced partially with Byzantine Empire, the Aksumite achieved major historical grounds, Orthodox Tewahedo Christianity introduced and has been state religion in the early 4th century, construction of stone-fitted palace and public buildings, and erection of large obelisks around the capital Axum.

He denoted these people locating in the place superimposed by Nubia and Meroë, connected to the Nile river, having distinct rainy season and wonderful lake.

Aksum's power began declining at the time of the Islamic Golden Age, where they frequently countered intrusions by Arab Muslims in the South Arabia protectorate (modern Yemen), making them to evicted more in the southern of Agaw population.

The successful integration of Agaw and Semitic groups in the north prolonged over millennium and eventually forms Tigrayans and Amhara people.

A dominant group, Amhara, continues to expand its territory in so-called Solomonic period after the downfall of Zagwe in 1270, and by the late 13th century, they reached to southern Shewa.

Since then, centralized military unit was buildup while frequently engaged war with Sidama kingdom in the west and Muslim population to the east.

Tewodros II is often credited with being the preliminary figure of modern Ethiopian history but his reign ended prematurely when he committed suicide during the British Expedition to Abyssinia.

[48] According to Aaron Matteo Terrazas, "if the descendants of Ethiopian-born migrants (the second generation and up) are included, the estimates range upwards of 460,000 in the United States (of which approximately 350,000 are in the Washington, DC Metropolitan Area; 96,000 in Los Angeles; and 10,000 in New York).

There are also large number of Ethiopian emigrants in Saudi Arabia, Italy, Lebanon, United Kingdom, Canada, Sweden and Australia.

[49] An investigation by Tishkoff et al. (2009) identified fourteen ancestral population clusters which correlate with self-described ethnicity and shared cultural and/or linguistic properties within Africa, in what was the largest autosomal study of the continent at the time.

"[52] Other studies conducted on Ethiopians belonging to Semitic and Cushitic ethnic groups mostly from the north of the country (Oromo, Amhara, Tigray, and Gurage), estimate approximately 40% of their autosomal ancestry to be derived from an ancient "non-African" back-migration from the Near East and about 60% to be of native African origin (from a population indigenous or "autochthonous" to the Horn of Africa).

"[56] In characterizing the ancestry, Pagani, Luca et al. (2012) noted this non-African component is estimated to have entered the Horn of Africa roughly ~3,000 years ago, and was found to be similar to the populations in the Levant.

[57] Gallego Llorente, M et al. (2015) similarly discovered extensive admixture in Eastern Africa from a population closely related to early Neolithic farmers from the Near-East/Anatolia.

The modern-day Nilotic groups are likely direct descendants of past populations living in northeast Africa many thousands of years ago.

Overall, the study revealed that groups belonging to the Cushitic, Omotic, and Semitic branches of Afro-Asiatic in the region, still showed high genetic similarity to each other on average.

Restricted to Africa, and mostly found along the Rift Valley from Ethiopia to Cape Town, Haplogroup A represents the deepest branch in the Human Y- Chromosome phylogeny.

"[53] Scott et al. (2005) similarly observed that the Ethiopian population is almost equally divided between individuals that carry Eurasian maternal lineages, and those that belong to African clades.

The authors noted: "Detailed phylogeography of HV1 sequences shows that more recent demographic upheavals likely contributed to their spread from West Arabia to East Africa, a finding concordant with archaeological records suggesting intensive maritime trade in the Red Sea from the sixth millennium BC onwards.

The authors indicate that: "The most frequent haplotype in west coastal Yemen is 16126–16362, which is found not only in the Ethiopian highlands but also in Somalia, lower Egypt and at especially high frequency in the Nubians.