In the late 1930s and early 1940s, a time of great immigration of Italians into the then colony of Eritrea, this apostolic vicariate, which since 1930 was exclusively of the Latin Church, happened to have more faithful than the Ordinariate for the Ethiopic Rite Catholics in the country; but after the Second World War the number of Italians in Eritrea went into steep decline.

The building in the Lombard Romanesque style was designed by the Milanese architect Oreste Scanavini and work on it was supervised by Mario Mazzetti from Montese in the Italian province of Modena.

[1] The main initiative for building the great church came from Camillo Francesco Carrara, O.F.M.Cap., titular bishop of Agathopolis, who was the first Apostolic Vicar of Eritrea.

The painting by Carlo Maratta (1625–1713) behind the high altar, representing the Assumption of Mary, was a gift from King Victor Emmanuel III of Italy.

The church was partially damaged during WW2, but it was quickly repaired in the following years thanks mainly to the contributions of the Italians living in Asmara.