The Mother Cathedral of Holy Etchmiadzin was called St. Kathoghike of Vagharshapat, and the Holy Altar was called Shoghakat Holy Mother of God.
According to the testimony of Agathangelos, was built with the vision of St. Gregory the Illuminator, near the palace of the king. According to the vision, inside the Cathedral- under the dome, the Holy Altar of Descent was established (reconstructed in 1961, according to the project of architects A. Galikyan and sculpting sketches by R. Israelyan). According to the national tradition, after the global flood, Patriarch Noah set up am altar there and offered a liturgy of satisfaction.
According to different points of view, the architectural design of the Mother Cathedral was a three-nave basilica: rectangular, four-sided dome, vaulted hall in the shape of a four-pillar cloud standing on the Holy Cross; originally built in the present invention.
According to Gazar Parpetsi, during the reign of Catholicos Hovhannes I Mandakuni, with the sponsorship of Vahan Mamikonyan, the Mother Cathedral was completely rebuilt in 483-484, following which it received its current basic appearance in terms of plan and volume.
This Armenian ecclesiastical invention of the cathedral, with a cross-central dome, four-aisled, four-chambered, is a great contribution to the world Christian architecture. This architectural invention was also spread in Europe in the 9th-11th centuries.
The cathedral was significantly damaged by Arab, Seljuk-Turk and Mongol-Tatar invasions. The name Etchmiadzin (Jesus descended) of the temple was used for the first time by the historian of the 13th century, Metropolitan Archbishop Stepanos Orbelian.
At the beginning of the 17th century, Persian Shah Abbas I initially decided to demolish the Cathedral. Fortunately, this malicious goal was prevented by the efforts of Khoja Nazar, but later, in 1614, 15 stones were removed from the Cathedral from key places, which were transported to Persia, in order to build a new cathedral in the likeness of the Cathedral near Isfahan, so that the hearts of thousands of Armenians displaced from their homeland "would not be crushed by longing". During the mentioned period, the cover and dome of the Cathedral were destroyed, many stones of the walls were thrown, the foundations were damaged and the cathedral was looted.
The current dome of the structure dates back to the 17th century, and the portraits of the apostles are carved in the form of medallions on the 12 sessions of the drum (according to the conviction of the doctor of architecture A. Ghazaryan, the sculptures are dated earlier), and brief memorials have also been preserved near them. Apparently, the names of masters and sponsors are mentioned.
Excavations in the 1950s revealed the cross anchors of the 4th-century dome-bearing gables, a monument from the Van Dynasty under the Senior Altar (currently erected in the courtyard in front of the bell-tower) and the initial altar with a central oven-shaped firebox.
Among the renovation works carried out so far, let's highlight the following:
In the second half of the 4th century, the Mother Cathedral, heavily damaged by the Persian invasions of Shapuh II, was rebuilt during the reign of Nerses I the Great, in 353-373. Works were also carried out during the reign of Sahak I Parthev, in 387-428, and in 483-484 was rebuilt by Marzban Vahan Mamikonyan with new architectural solutions and similar to today's structure. In 615-628, during the reign of Komitas I Aghdzetsi, the wooden covering of the Cathedral was replaced with stone, and then repaired during the reign of Catholicos Nerses III Tayetsi in 641-661. After a long hiatus, in 1441-1465, renovation works were carried out during the reign of Catholicos Kirakos I of Virap and Grigor X Jalalbekyants. From 1629 to 1632 "on the basis of" it was renovated and supplemented with new buildings during the reign of Catholicos Movses III of Tatev. In 1632-1655, during the reign of Catholicos Philip I Aghbaketsi, the stone roof of the Cathedral was rebuilt: the construction works of the three-story bell tower have begun. In 1657-1658, during the reign of Catholicos Hakob IV of Jugha, the construction of the bell tower was completed.
In 1681-1691, Catholicos Yeghiazar I of Aintap built bell-domes on three altars and covered the floor of the cathedral with marble. In 1720, by the order of Astvatatur I Hamadantsi (1715-1725), Naghash Hovnatan started the illustration of the temple. In 1726-1729, during the reign of Catholicos Karapet II Ulnetsi, the series of 15 icons of the stage was realized. In 1770 Catholicos Simeon I of Yerevan rebuilt the stone roof of the Cathedral, and Catholicos Ghukas I Karnetsi strengthened the foundation of the Cathedral in 1789. In 1804-1813, during the Russian-Persian war, the church was neglected and destroyed. In 1837, during the reign of Catholicos Hovhannes V Karbetsi (1831-1842), on the occasion of the visit of the Russian Emperor Nikolai I, small-scale repair works were carried out. In 1888, during the reign of Catholicos Makar I of Teghut (1885-1891), the interior of the cathedral was renovated.
In 1914, during the reign of Catholicos Gevorg I Surenyants (1911-1930), the interior of the cathedral, the bell tower and the southern altar were renovated again. In 1945-1954, during the reign of Catholicos Gevorg VI Chorekchyan, the cathedral was repaired and updated.
In 1955-1959, during the reign of Catholicos Vazgen I Palchyan (1955-1994), restoration works were carried out, archaeological excavations were carried out under the Holy Altar, in 1981-1982 the frescoes were repaired and restored, and the museum part was decorated anew. In 2001-2008, during the reign of Catholicos of All Armenians Karekin II, with the benevolence of famous American-Armenian philanthropists Richard and Louise Manoogian, a complete renovation of the roof coverings, interior murals, prayer hall floor, wall anchors, museum section, Holy Altar of Descent, and repair of the lower damaged parts of the table and tombstones of Catholicos were implemented. From 2012 until now, complex and fundamental repair works are being carried out, which are planned to be completed in 2024.