February 1975: The Tigray People's Liberation Front (TPLF) is founded

After Emperor Haile Selassieis overthrown in the 1974 revolution, a military junta known as "The Derg" quickly fills the power vacuum. The subsequent civil war has a devastating impact on the country, including the Tigrayan people in the north. Tens of thousands of young people are murdered in a brutal political repression campaign known as Ethiopia's "Red Terror." To fight back and destabilize the junta, eleven men establish the Tigray People's Liberation Front (TPLF). 

Read more: Ethiopia's Abiy vows 'final' phase in Tigray conflict

June 1991: TPLF overthrows the government

In less than two decades, the TPLF evolves into the most powerful armed liberation movement in Ethiopia. In 1991, TPLF and coalition partners defeats the military government. For another two decades, the TPLF dominates Ethiopia's ruling alliance, the Ethiopian People's Revolutionary Democratic Front (EPRDF). During its 27 years in power, child mortality rates fall, and large-scale famine is banished. But Ethiopia remains a one-party state, and a growing generation of youth feels increasingly excluded and disillusioned by the apparent domination of Tigrayan politicians. Abiy and his supporters refer to this period as "27 years of darkness."

April 2018: Abiy Ahmed sweeps to power after a popular uprising

After years of anti-government protests, Hailemariam Desalegn steps down as prime minister. Abiy Ahmed is elected leader by the EPRDF, becoming the country's first Oromo leader – Ethiopia's largest ethnic group, which for years claimed to be marginalized by the EPRDF. During his acceptance speech, Abiy promises significant political reform and unity among the Ethiopian people, sparking optimism even among opposition groups.

Read more: Ethiopia: Who is new Prime Minister Abiy Ahmed Ali?

2018 – 2020: Abiy implements wave of reforms

True to his word, Abiy begins implementing many of his reforms. Ethiopia – and the world – watches closely as he releases thousands of political prisoners, unblocks hundreds of media channels, and privatizes state-own enterprises. In 2019 he is awarded the Nobel Peace Prize for resolving the long-running conflict between Ethiopia and Eritrea.

But Abiy's reforms also upend the country's long-established power dynamics. Tigray's leaders say they are unfairly targeted in corruption trials and used as scapegoats for the country's problems. In 2019, the TPLF refuses to join Abiy in forming the nationwide Prosperity Party after Abiy dissolves the EPRDF, which was dominated for decades by the Tigray People's Liberation Front.

August – September 2020: COVID-19 hits, and elections are postponed

Abiy postpones the much-anticipated August 21 general elections as the coronavirus pandemic takes hold in Ethiopia. His decision doesn't sit well with the TPLF party, which accuses Abiy of unconstitutionally extending his government's term. In defiance, they create their own electoral commission and hold separate regional elections. Abiy's government, in turn, accuses the TPLF of unlawfully holding their own polls, further raising tensions.

Read more: Opinion: Ethiopia is on the brink of failure

November 4, 2020: Tigray regional forces launch surprise attack

Security forces loyal to the TPLF unexpectedly attack the Northern Command of the Ethiopian National Defense Force (ENDF) in Tigray region's capital, Mekele. Several people are killed. The TPLF claims the strike was carried out in "self-defense."

Abiy responds by saying the TPLF has "crossed a red line" and a military offensive will be launched. Authorities shut down internet, telephone, and electricity services in Tigray, while the Tigray Regional Administration forbids all forms of transportation, including flights.

November 6, 2020: Abiy government launches counter-airstrike

Abiy confirms his government launched an airstrike against Tigray forces, destroying many rockets and other weapons. He also claims the TPLF rejected the government's attempts at "mediation, reconciliation [and] dialogue."

Sudan responds to the escalation in violence by closing its borders with Ethiopia, while the United Nations (UN) urges a swift and peaceful resolution.

November 7, 2020: Parliament declares Tigray government illegal

During an emergency session, Ethiopia's parliament deems the Tigray government illicit and votes to form an interim government for the northern region.

Read more: Ethiopia's spiraling conflict threatens regional stability

November 9, 2020: Mai Kadra massacre

Against the backdrop of ongoing battles between the Ethiopian federal government and Tigray forces, up to 500 civilians are killed in a massacre in Mai Kadra near the Sudanese border. According to Amnesty International, witnesses say Tigray forces were responsible for the killings after suffering a defeat from the federal government forces.

November 10-13, 2020: Refugees on the move

As sporadic violence continues in the north, a wave of refugees flees to neighboring Sudan. On November 11, approximately 10,000 refugees are reported to have crossed the border, including many soldiers. That number has since increased to 25,000, according to Sudanese officials.

Read more: Ethiopian PM 'at war' with Tigray

November 14, 2020: Rocket attacks in Asmara

Multiple rockets launched from Ethiopia hit Eritrea's capital, Asmara. TPLF leader Debretsion Gebremichael says Asmara was a "legitimate target" because Ethiopian government forces were using its airport to carry out attacks on TPLF fighters. While Eritrea continues to deny its involvement in the conflict, the attack fuels ongoing concerns of a broader regional conflict. UN Secretary-General Antonio Guterres warns the fighting must not escalate further, saying, "Ethiopia's stability is important for the entire Horn of Africa region."

November 23, 2020: Mekelle surrounded 

According to a government spokesperson, Ethiopian federal forces have surrounded Mekelle at about 50 km (31 miles). The government also alleges that Tigrayan forces have fired rockets into Bahir Dar, the neighboring Amhara region's capital.

The TPLF accused Abiy's government of "invading" their region to subjugate the population. TPLF claims government troops have inflicted "merciless" damage on Tigrayans.

State-affiliated media reports suggest that TPLF fighters have destroyed an airport in the ancient city of Axum. The town, which lies northwest of Mekele, is a popular tourist attraction and a UNESCO World Heritage site.

November 26, 2020: Abiy orders "final phase" on Mekele

Ethiopia's Prime Minister Abiy Ahmed orders the National Defense Force to attack Mekele and "bring to justice" TPLF leaders. In a tweet, he says thousands of TPLF fighters have surrendered.

Abiy remains opposed to any international mediation efforts, telling those seeking to pressure him to the negotiating table to "stand by" until Ethiopia's government requests assistance.

Previously, TPLF leader Debretsion Gebremichael vowed that his people are ready to die defending their right to "self-rule."

There are also concerns a protracted conflict in Ethiopia could impact the already-fragile Horn of Africa, especially in neighboring countries including Somalia, Eritrea, Djibouti, and Sudan.