The Moscow Prince Ivan Kalita, seeking to unite the Russian lands under his principality, planned to make Moscow a pan-Russian political and religious centre. To this end, he invited Metropolitan Peter of Vladimir to settle in Moscow, and from 1326 the city became the capital of the Russian metropolitan see. The growing prosperity of Moscow allowed the construction of white stone churches to begin in the Kremlin, the Prince's residence. The first was the stone Church of the Assumption of Our Lady, built in 1326 on the highest point of the Kremlin Hill on the site of an earlier, probably wooden, one. It was conceived by Metropolitan Peter and Ivan Kalita as the first capital temple of the Moscow State and the burial place of the Moscow metropolitans. The foundation stone was laid by the first hierarch of Moscow himself, and the cathedral was consecrated on 14 August 1327, the eve of the Assumption of the Theotokos feast. Metropolitan Peter died before the construction was completed and was buried on the north side of the temple near the altar.

In 1329 a side church was built above the entombment of the first Moscow hierarch in honour of St Peter the Apostle’s – the patron saint of the Metropolitan – liberation from the precious chains. It was built within two months after the peaceful settlement of the conflict, probably under oath, with the people of Pskov.

Foundation of the Assumption Cathedral by Metropolitan Peter in 1326Peter Lays the Foundation of the Assumption Cathedral in the KremlinThe Assumption Cathedral on the margin ‘Praying by Peter’s Coffin’

Like all subsequent religious buildings of the Kalita era, the first Assumption Cathedral was built "in one summer" and was therefore of small size. Its builders are unknown. They were probably inhabitants of Vladimir or Tver, who had mastered the art of building in white stone before the Muscovites. Rare chronicles and iconographic materials, together with field data from the archaeological survey carried out by the museum in the 1970s allow hypothetical reconstruction of its configuration. It was a church with four pillars, three apses, a single dome, three lowered narthexes and a side chapel on the north side with the tomb of Metropolitan Peter. Such an interpretation does not contradict the appearance of the building during its construction, although very conditional, on the icon of the early 15th century, when the church still existed. The Cathedral of St George in Yuriev Polsky built in 1234 had a similar design.

There is even less information about the external architectural appearance of the ancient Cathedral of the Assumption. It is depicted on the margins of the icon "Metropolitan Peter with Scenes from His Life" from the last quarter of the 15th century as a one-dome church with a complex plan and arched gables under the roof. The icon "Metropolitan Alexius with Scenes from His Life" by the same author shows a similar image. Taking into account the ecclesiastical tradition of copying in liturgical objects the architectural forms of the buildings for which they were intended, it can be assumed that the Great Zion vessel (dated 1486) from the Armoury Chamber was a reproduction of the ancient Assumption Cathedral – single-domed with a cupola roof and three-lobed ogee arches at the base of the cupola. Archaeological finds in the area of the present Assumption Cathedral indicate the presence of carved decorations on thefaçades of the ancient temple.

The cathedral originally had a side chapel dedicated to St Demetrius of Thessaloniki, apparently in the southern apse. In 1344, the cathedral was painted by Greek masters, decorated with icons and precious ecclesiastical objects. In 1459, under Metropolitan Jonah, a side chapel of the Glorification of the Mother of God was added to the south side of the Cathedral as well.

After a century and a half, the dilapidated and cramped church no longer corresponded to the growing importance of the Moscow principality, and by 1472 it was demolished to make way for the present wide Assumption Cathedral, which reflected the new social and political importance of the Moscow state as the centre of the Russian land.

The Grand Zion vesselAssumption Cathedral of 1326-1327Plan of the Assumption Cathedral of 1326-1327