Boma

City · c. 1908 CE · in Sub-Saharan Africa

Capital of Belgian Congo (1908–1960).

Port Vila (c. 1907 CE): Capital of New Hebrides (1907–1980), Vanuatu (1983–today).
Kigali (1907 CE): Capital of Republic of Rwanda (1963–today).
Dodoma (1906 CE): Capital of Tanzania (1996–today).
Lusaka (1905 CE): Capital of Zambia (1967–today).
Gitega (1912 CE): Capital of Republic of Burundi (2019–today).
Canberra (1913 CE): Purpose-built capital of Australia, named in 1913 and designed by Walter Burley Griffin and Marion Mahony Griffin; Parliament moved there in 1927.
Nizwa (c. 1913 CE): Capital of Imamate of Oman (1913–1919).
Lilongwe (1902 CE): Capital of Malawi (1975–today).
Mbabane (1902 CE): Capital of Eswatini (1969–today).
N'Djamena (1900 CE): Capital of Republic of Chad (1961–today).

Around the same time and place

Scramble for Africa (1881–1914 CE): Invasion, occupation and partition of almost all of Africa by European powers between the 1880s and 1914, formalised in part at the Berlin Conference of 1884–85.
HIV/AIDS pandemic (c. 1920 CE): Genetic studies trace the pandemic strain of HIV-1 to Kinshasa around the 1920s; AIDS was identified in 1981 and has killed tens of millions of people, with sub-Saharan Africa most affected.
Kingdom of Kongo (c. 1390–1914 CE): Central African kingdom with its capital at Mbanza Kongo; after Portuguese contact in 1483 its rulers adopted Christianity, and it later became deeply entangled in the Atlantic slave trade.
Congo Free State (1885–1908 CE): Colony privately ruled by King Leopold II of Belgium, where forced labour for rubber collection caused mass deaths; international outcry led Belgium to annex it in 1908.
Brazzaville (1880 CE): Capital of Free French (1940–1943).
Yaoundé (1888 CE): Capital of Republic of Cameroon (1960–today).
Bangui (1889 CE): Capital of Central African Republic (1961–today).
Patrice Lumumba (1925 CE – 1961 CE): First prime minister of the independent Congo, deposed months after independence and executed in Katanga in January 1961.