It was built to commemorate the Ethiopian victory over Italian occupation and is an important place of worship in Ethiopia, alongside other cathedrals such as the Church of Our Lady Mary of Zion in Axum.

Built in 1942,[1] the church compound was the burial place for those who fought against the Italian occupation, or those who accompanied the Emperor Haile Selassie into exile from 1936 to 1941.

Other facilities include a primary and a secondary school, a monastery and the Holy Trinity Theological College, a museum and monuments housing the remains of those massacred in Addis Ababa by the Italians in 1937 in response to an assassination attempt against Marshal Rodolfo Graziani, Viceroy of Italian East Africa.

The tombs of the Emperor Haile Selassie and the Empress Menen Asfaw, as well as other members of the Imperial Family, are inside Holy Trinity Cathedral.

Patriarchs, Abuna Takla Haymanot and Abune Paulos of the Ethiopian Orthodox Tewahedo Church, are buried in the churchyard, as is the famous British suffragette and anti-fascist activist Sylvia Pankhurst.