In the 19th century, Sourp Nichan (St. Nichan) Cathedral, along with its adjoining spiritual house, served as a pilgrims’ station for those journeying to Jerusalem. The church was overseen by a priest from the Armenian Patriarchate of Jerusalem. Thus, before the establishment of an Armenian prelacy in Lebanon, Armenians maintained a pilgrims’ station. During the First World War, Sourp Nichan Church was captured and demolished by the Ottoman government under the pretext of road expansion. However, under the leadership of Catholicos Sahag Khabayan (Catholicos Sahag II), approval to construct a church was obtained from the French High Commissioner.

In 1924, the French High Commissioner recognized the prelacy in Lebanon as part of the Holy See of Cilicia.

In 1925, Catholicos Sahag II appointed a Vicar-General to the prelacy and demanded the election of a Diocesan Executive Council. In 1926, the first meeting of the Diocesan Representative Assembly was held.

In 1929, His Holiness Sahag Khabayan wrote a letter to the Patriarch of Jerusalem, Archbishop Yeghisheh Tourian, reporting the latest developments. In his reply, Archbishop Tourian transferred the churches, monasteries, and schools in Lebanon and Syria, originally under the jurisdiction of the Armenian Patriarchate of Jerusalem, to the Holy See of Cilicia.

In 1938, with the financial support and efforts of the Armenians in Lebanon, Sourp Nichan Church was reconstructed after demolishing the old one.

In 1951, Bishop Khoren Paroyan was elected as the first Prelate of the Armenian Prelacy of Lebanon. Before this date, the Catholicosate had Pontifical Vicars and Locum Tenets.

In 1963, the inauguration of the new Prelacy building took place, next to Sourp Nichan Church.

In 2010, the construction of the new Prelacy building in Bourj Hammoud took place.