Unity Park in Addis Ababa, a monument of historical and cultural significance, was inaugurated on January 20, 2019. The park, located at the National Palace, represents Ethiopia's rich history and diversity. It includes preserved and restored historical buildings, showcases Ethiopia's natural and cultural heritage, and serves as a symbol of national unity and peace.

On January 28, 2013, a new headquarters for the African Union was inaugurated in Addis Ababa. The building was a gift from the Chinese government and represents the growing relations between Africa and China. It serves as the symbol of African unity and progress, hosting numerous important summits and diplomatic gatherings, showcasing Addis Ababa's role as a diplomacy hub.

On May 28, 1991, the Derg regime in Ethiopia collapsed as the Ethiopian People's Revolutionary Democratic Front (EPRDF) forces, along with allied militias, entered the capital, Addis Ababa. This marked the end of nearly two decades of Marxist rule and the beginning of a new era focused on multi-ethnic federalism and economic restructuring.

On September 12, 1974, a military junta known as the Derg overthrew Emperor Haile Selassie, marking the beginning of a socialist regime in Ethiopia. This revolution drastically altered the political landscape of Addis Ababa as the new government nationalized key institutions and land, and it led to years of political turmoil and conflict within the country.

Addis Ababa was selected as the headquarters for the newly formed Organization of African Unity (OAU) on May 25, 1963. The OAU aimed to promote unity and cooperation among African countries and played a crucial role in the politics of Africa, including supporting independence movements. The organization's headquarters made Addis Ababa a major political hub.

On May 5, 1941, five years to the day after it was captured by Italian forces, Addis Ababa was liberated by Ethiopian and British troops. This was a pivotal moment in Ethiopian history as it restored sovereignty to the nation and marked the end of Italian occupation. Haile Selassie returned to Addis Ababa triumphantly shortly thereafter.

On May 5, 1936, Italian forces captured Addis Ababa, marking the beginning of Italian rule in Ethiopia. This event was part of the Second Italo-Ethiopian War. The occupation led to significant efforts by the Italians to modernize the infrastructure of the city, although it also involved brutal repression of the Ethiopian population. The occupation lasted until 1941.

Emperor Haile Selassie I was crowned on November 2, 1930 in Addis Ababa. His coronation was a significant event attended by numerous international dignitaries, symbolizing Ethiopia's emergence onto the world stage. Haile Selassie's reign is noted for modernization efforts and his role in the foundation of international organizations, his legacy remains influential.

In 1911, the railway from Djibouti reached Addis Ababa, significantly impacting the city's growth and development. The railway facilitated trade, enabled easier access to the coast, and integrated Addis Ababa more firmly into the global economy. It also stimulated urban migration and the development of the city's infrastructure.

Addis Ababa was founded by Emperor Menelik II in 1886. It became the capital city of Ethiopia due to its strategic location, natural resources, and favorable climate. The city grew rapidly as Menelik II’s political and commercial center. The city’s name meaning 'New Flower' was given by Empress Taytu, Menelik's wife.