In the East Africa Campaign of World War II, the Greater Horn of Africa sees hostilities between Great Britain, Ethiopia, France and Italy. Italian East Africa (AOI) — comprising Ethiopia and its Ogaden region, Eritrea and Italian Somaliland — falls under British control. Eritrea and Somaliland remain British Military Administrations for nearly a decade. The British and Ethiopian armies expel Italian forces from Ethiopia, restoring native imperial rule to the country.
Italian Somaliland leaves British hands to become the UN Trust Territory of Somalia, which Italy administers. This marks Italy’s last colonial territory post-World War II. The UN General Assembly resolution stipulates that the territory will transition into an independent, sovereign state within ten years. However, the United Nations solely negotiates the Trusteeship Agreement with Italy, excluding Somali representatives.
At that same meeting, the UN passes a resolution on Eritrea’s status relating to the Ethiopian Empire. The mandate establishes Eritrea as a temporary autonomous federal province for a ten-year transition period. After a territorial election in March 1952, a coalition government forms in the Eritrean Assembly and adopts the Eritrean Constitution on July 10. Ethiopian Emperor Haile Selassie I ratifies the Eritrean Federation on September 11 and Britain relinquishes control on September 15.
Sudan elects its first self-governed parliament amid a cultural–religious divide between the Muslim North and the predominantly Christian South. Northerners dominate many army and administrative positions after decades of colonial policies closed the Southern provinces to curb Islamic cultural influence. As a result, Southerners have lower educational, political and economic prosperity. The North sees South Sudan as uncivilized and unqualified for high-ranking positions. Southerners lament the bias.
The First Sudanese Civil War (or the South Sudanese War of Independence) breaks out. The new government fires and imprisons Southern MPs, police fire on Southerners protesting work dismissals and a fake telegram frames instructions for officials to persecute the South Sudanese. Conspirators in the South spread rumors of a coming incursion, making Southern soldiers rebel. Mutineers take military bases and kill Northern officers. The unrest ends in September, but marks the start of a long, bloody conflict.
The British–Egyptian joint government, the Anglo–Egyptian Condominium, grants Sudan its independence. In the transition from colonial to native rule, disorganized political parties hold loose alliances based on self-interest and religion. Liberal democracy falls on November 17, 1958, as Brigadier General Ibrahim Abboud overthrows the government in a coup d’etat and enacts more discriminatory policies against the South, intensifying the civil war.
On June 26, Northern British Somaliland gains its independence. Southern Italian Somaliland follows on July 1. The countries unify without a vote, becoming Somalia, or the Somali Republic. The new National Assembly forms with 33 members from the North and 90 members from the South. Somalia actively supports secession efforts abroad in French Somaliland, Ethiopia and Kenya — a popular policy. Major Northern and Southern parties support the first coalition government, though clan interests soon divide the country.
From the 1950s, Ethiopian interference disregarded the Eritrean Constitution. They eliminated local languages from schools, banned trade unions and political parties, and denied Muslims public employment. The Eritrean War of Independence begins over these conditions on September 1, 1961. Pro-secession leaders mobilize a guerrilla force and form the Eritrean Liberation Front (ELF). The ELF seeks support from Sudan and other Islamic states. Eritrean Christians also join the ELF, protesting banned languages.
The Ethiopian parliament responds to Eritrean militant resistance by voting to end Eritrea’s autonomy. Intelligence uncovers a plot to assassinate Eritrean Chief Executive Asfaha Woldemikael and Selassie, and authorities arrest several convicted Eritreans. Concerned for the safety of their leadership, Eritrean authorities unanimously agree to become a province of Ethiopia. The decision’s legality faces scrutiny and proves unpopular among Eritreans.
Somalia cuts ties with Britain, and a four-year guerrilla war begins as Kenyan Somalis fight for self-determination. Soon after, Kenya gains independence from British colonial rule on December 12, electing the popular candidate Jomo Kenyatta as prime minister. Somali secessionists in Kenya boycott elections and demand union with Somalia, engaging in ambushes and attacks on police posts. Kenya refuses to acknowledge ethnic irredentist movements, and a ceasefire ends the main conflict in 1967.
Ethnic Somalis in Ethiopia, known as Ogaden, reject taxes and cultural assimilation with Ethiopia, and launch the Ethiopian–Somali Border War (or the First Ogaden War). The young Somali army helps Ogaden insurgents but lacks advanced equipment. Ethiopia’s brutal military campaign suppresses the population, killing livestock and denying civilians access to water. The war creates a demilitarized zone and damages Ethiopian–Somali relations. It marks the first international war on the African continent since independence.
A referendum happens in French Somaliland, also called the French Somali Coast. The vote, including European settlers, renews the territory’s association with France and renames it the French Territory of the Afars and the Issas — two major ethnic groups. French authorities control voting rights to steer referendum results in their favor. Though the population structure barely changes in the years leading up to the vote, Afar voters increase by 195% while ethnic Somali Issa voters increase by 55%.
Anti-Christian policies persecute Southerners on the orders of multiple civilian-led and military governments. Militant Southerners clash with the government, and both militaries commit violent atrocities. The First Sudanese Civil War killed 500,000 to one million people over its 17-year campaign; civilians suffered the most. On March 27, 1972, the war ends with the creation of the Southern Sudan Autonomous Region (SSAR).
The Derg, a military junta made up of low-ranking police and Ethiopian army members, overthrow the Ethiopian Empire, starting the Ethiopian Civil War. They create Socialist Ethiopia and attempt to solve food scarcity through state-controlled land reforms, though droughts and a lack of farming incentives instead create famine. They also enact counterinsurgency measures to repress the Eritrean People’s Liberation Front (EPLF) and Ogaden insurgents in the South, mirroring the empire’s previous policies.
At the mouth of the Red Sea and the Indian Ocean, the French Territory of the Afars and the Issas, now named Djibouti, votes and wins independence. The Somali-led opposition backs the popular referendum and politician Hassan Gouled Aptidon while the Afars boycott the vote. Afar-dominated regions see low voter participation, and the motion passes almost unanimously. The Djiboutian National Assembly declares Aptidon Djibouti’s first president. France cedes control but keeps an active military base there.
Thirteen years after the First Ogaden War, violence erupts between Somalia and Ethiopia. Both socialist countries claim the Ogaden land, and Cuba- and USSR-mediated talks break down. Civil unrest worsens as Ogaden insurgents warring with Derg leader Mengistu Haile Mariam receive Somali military aid. Somalia takes much of the region using Soviet weapons, though they later lose USSR support and align with the United States. Ethiopia switches from US to Soviet support and wins this year-long war.
The Derg invade central Somalia, initiating the Second Ethiopian–Somali Border War. Their goal to split Somalia in half almost immediately fails as Ethiopian troops cannot occupy a strategic arterial crossing that links the eastern capital to the North. Despite equipment shortages, Somali President Siad Barre leads this offensive. The fighting ends in a year. Previously, Somali military forces infiltrated the Ogaden multiple times, only withdrawing on US demands.
The Second Sudanese Civil War (or the South Sudanese War of Independence) breaks out. Sudanese Military President Gaafar Muhammad al-Nimeiri declares Sudan an Islamic state and dissolves Southern autonomy. Though Nimeiri signed the SSAR agreement himself a decade earlier, he now repeals it, and war reignites. To crush Southern rebels, the Sudanese army cuts food supplies and creates widespread famine. The US arms the North as Ethiopia supports the South. This round of war kills up to 2.5 million people.
After nearly a decade at war, Barre and Mengistu sign a peace accord. Since the early 1980s, Central and Northern Somalia saw guerrilla operations organized from within Ethiopia. Somalis also supported Ogaden rebels at that time. War in Eritrea ramps up, and Ethiopia seeks an agreement with Somalia as the army can no longer sustain wars on multiple fronts. They agree to demilitarize the common border, restore diplomacy, return prisoners and end funding for insurgent groups.
Since 1960, Barre killed hundreds of thousands and imposed a ten-year curfew on the North to curb resistance groups. Losing the Ogaden War destabilized his support in Somalia. Though he outlawed clan loyalties in the 1970s, his own clan dominates the government. In the late 1980s, Barre committed genocide in Somaliland, razing entire cities. On May 18, 1991, Somaliland declares its independence, launching the Somali Civil War. Somalis oust Barre, and the rule of law breaks down for two years.
The Soviet Union cuts its military aid to Ethiopia, signaling the decline of Ethiopian military campaigns. Eritreans increasingly join rebel groups as the Derg indiscriminately attack civilians. Defeated by guerilla forces, Ethiopia’s government loses control of Eritrea. The countries separate after 30 years of war, and Eritrea officially gains its independence in 1993 following a referendum vote. This is one of the first instances of territorial secession in post-colonial Africa.
The Tigray People’s Liberation Front (TPLF) pushes toward the capital. A combined effort by government officials and rebels overthrows Mengistu, who flees the country. The Derg tries to hold power, but the Ethiopian People’s Revolutionary Democratic Front (EPRDF) ousts them in a week. Derg leaders face charges of genocide as this 17-year war killed at least 1.4 million people through famine and violence. Ethiopia adopts a federal democracy.
In 1981, Issa leaders in Djibouti banned opposition parties and expelled Afar leaders accused of inciting ethnic conflict. Tensions rose between these two ethnic groups, as Afars made up a third of the national population. On October 31, 1991, the Djibouti Civil War (or the First Afar Insurgency) begins. The Afar group FRUD launches guerrilla attacks and eventually controls most rural areas. Global observers believe elections are fraudulent. In 1994, the war concludes as internal dissent splits FRUD.
Military observers arrive in Somalia under UNOSOM (United Nations Operation in Somalia) to monitor the ceasefire and civil war. Over half the population faces starvation and disease due to capital power struggles. The UN uses any means necessary to secure the area as the fighting continues, and relief operations face risks. These operations will cause the infamous Black Hawk Down affair in fall 1993. Many peacekeeping forces commit human rights abuses against civilians and withdraw without completing their objectives.
Ethiopian forces launch an attack against the local Islamist group AIAI to suppress it, killing its top leaders. Somali groups seeking self-determination from Ethiopia fight in the insurgency. Insurgents in the region seek help from rebel groups across the country, including the TPLF and Afar insurgents. To counter this, the EPRDF intensifies operations and imprisons and kills local Somali leaders. A regional paramilitary later develops across the country to police all turbulent regions.
In Eritrea and Ethiopia, Afar secession groups wage war. The region the Afar traditionally inhabit intersects with three countries: Eritrea, Ethiopia and Djibouti. Tensions come to a head, and the Afar Revolutionary Democratic Unity Front (ARDUF) launches attacks in Ethiopia, allegedly with Eritrean support. Essentially a local proxy war, each country backs different Afar rebel groups. The insurgency sporadically occurs over the next 23 years.
The Eritrean National Assembly elected President Isaias Afwerki in the 1993 referendum, leading to power consolidation and postponed elections. Disputes over shared borders escalate, culminating in armed conflict in 1998, when Eritrean troops cross the border. Ethiopia mobilizes a total war response, taking a quarter of Eritrea’s territory in two years despite accepting a peace plan. Eritrea agrees to a ceasefire, Ethiopia restores prewar borders and declares victory, and border skirmishes continue for decades.
Sudan’s government and the Sudan People’s Liberation Movement (SPLM) sign a comprehensive peace agreement, ending 22 years of civil war. The deal provides for a six-year transition period, power-sharing and a future referendum on Southern independence. South Sudan saw mass internal conflict throughout the war; local infighting killed more Southerners than Northern forces did. The war’s violence and famine killed an estimated two million people.
Ethiopia declares war on the Islamic Courts Union (ICU), a coalition of local Islamist courts, bombing targets and occupying Somali territory. Aided by the US, Ethiopia quickly moves through Somalia, taking the capital Mogadishu by January 2008. Twenty thousand civilians die from Ethiopian and insurgent violence. The troops leave in January 2009, having failed to dissolve Islamist insurgencies in favor of the Transitional Federal Government. ICU members later form Al-Shabaab, a shadow regime that extorts civilians.
Djiboutian authorities claim Eritrea is deploying military equipment unprovoked to the border region in Ras Doumeira. The cape serves as a critical access point to the Red Sea and a source of tension between the countries. Eritrean troops dig trenches and occupy the region. Negotiations fail and Djibouti, aided by France, sends forces to the border and reports to the UN. By June, clashes kill dozens. The conflict lasts until June, when Djibouti heeds UN advice and returns to its former positions.
The South Sudanese vote overwhelmingly for independence, with 99.57% choosing to secede from the North. The referendum fulfills a key provision of the 2005 peace deal. As only the third African nation to separate from a recognized nation, South Sudan becomes the world’s youngest country. However, the peace is short-lived, as a civil war erupts on December 15, 2013.
Kenyan troops intervene in Southern Somalia to combat crime and Al-Shabaab militants after several terrorist attacks and kidnappings. Somali President Sharif Sheikh Ahmed says he never agreed to Kenya’s incursion, but that Kenya consulted Ethiopia and Uganda. Somalia joins the security committee last. Ending in 2012, the intervention cost Kenya a monthly $180 million and 50 troops. In opposition, Kenya and Ethiopia support Somali regions to undermine federal power, rebuilding infrastructure but stoking tensions.
Ethiopia and Eritrea sign the Jeddah Agreement, formally ending the state of war between them. Upon entering office, Ethiopian Prime Minister Abiy Ahmed Ali renounces Ethiopia’s claim on territory disputed with Eritrea. The peace accord also ends the Second Afar Insurgency as proxy groups lose support from both countries. Altogether, the border conflict killed about 100,000 people.
With Abiy’s appointment, parliament lifts the ban on opposition groups, including the Ogaden National Liberation Front (ONLF). The groups agree to a ceasefire and disarmament, extending a peace deal to the ONLF. Federal troops move north for other insecure regions. The Ogaden Insurgency ends, though ethnic violence, intercommunal conflict, the cultural repression of Somalis, attacks from security forces and internal displacement continue.
South Sudan’s civil war displaces millions and kills 400,000 from violence, hunger and disease. President Salva Kiir Mayardit and Vice President Riek Machar fight for control, splitting the country along political lines with lasting tensions. Militias of various ethnic groups battle and attack civilians. Even after the leaders sign a peace agreement on September 12, 2018, civilians fear returning to their towns due to the continuing unrest and violence.
Since 2018, civil conflict worsened between Ethiopia’s federal forces and Tigrayan insurgents, leading to war in 2020. Abiy accuses the TPLF of attacking a federal military camp, and bloodshed begins. Tigrayan militants spill into neighboring regions and even manage to get close to the capital before troops repel them. Civilians suffer the most as the military allegedly perpetrates human rights abuses, war crimes and ethnic cleansing. A peace accord and relief finally arrive as the war ends in 2022.
War breaks out between the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF) paramilitary group. The conflict kills tens of thousands, displaces 14 million and triggers the world’s worst ongoing humanitarian crisis. Foreign interference shows both sides receiving major funding from large world powers. The constant flow of weapons further stokes violence. Foreign powers have strategic resource interests, with both the United Arab Emirates and Russia allegedly funding opposing groups to oversee Sudanese gold.
Jubaland, a federal member state in Southern Somalia, faces a constitutional crisis in March. The region opposes proposed federal electoral plans and temporarily suspends relations with its parent country. It demands independence amid Somalia’s ongoing federal–regional tensions, and begins fighting for it in December. After a year of clashes, in December 2025, Jubaland declares its independence. Kenya and Ethiopia allegedly funded Jubaland, which further complicates regional relations and Somalia’s national unity.
Somalia faces political fragmentation as more regional states demand autonomy, distancing themselves from federal governance. Puntland, a self-governed and clan-based Somali province since 1998, disagrees with the federally proposed constitutional amendments and withdraws from the federal system. It begins exercising de facto autonomy.
Despite a power-sharing agreement taking effect in 2020, on September 11, 2025, South Sudan’s government charges Machar with treason after his opposition forces seize an army base on the Ethiopian–South Sudanese border. The following January, the government launches an offensive in Jonglei State against his forces. Civilians evacuate as troops bomb the region, prompting accusations of ethnic cleansing. A staggering 3.2 million people face internal displacement.
Tensions restart as Ethiopia accuses Eritrea of funding Tigrayan rebels in September, though the two were allies during the Tigray War. Tigrayan rebels take control of many towns this time. Escalating further, a TPLF-led seven-group opposition alliance in Ethiopia opposes the government to overthrow Abiy. Ethiopia expels Eritrean diplomats, closes its embassy in Eritrea and alleges that Eritrean troops advanced into Tigray. Eritrea denies the accusation and severs diplomatic ties in response.
Credits
Researched and written by Aliyah A. Omar
Produced by Khemraj Singh & Netleon Technologies Team
Revised by Lee Thompson-Kolar
Images courtesy of Creative Commons & Shutterstock