The Church of Sts Constantine and Helen in the Kremlin was dedicated to the Roman emperor and his mother, canonised for having converted the Roman state to Christianity in the 4th century. The temple is first mentioned by chroniclers in 1470 in connection with a fire in Moscow. It was probably built of wood at that time and stood in the south-eastern corner of the town near the Timofeevskie Gates. The church was rebuilt after the fire; it is known that from 1490 those gates were called Konstantino-Eleninskie. The church was renewed in the 16th century by Elena Glinskaya, the mother of Ivan the Terrible.

It is supposed to have remained wooden until the middle of the 17th century. According to some reports, Tsar's father-in-law Boyar Ilya Danilovich Miloslavsky intended to build a stone church in 1651, but whether it was executed is unknown. In 1692, Tsarina Natalya Naryshkina, the mother of Peter the Great, financed the restoration of the church. It was consecrated on 4 December of the same year. That building existed until the first quarter of the 20th century.

The Church of Sts Constantine and Helen served as a parish for the clergy of the Assumption Cathedral, whose yards were located nearby. There was a cemetery near the church, which was closed in 1657.

In 1738 architect I.M. Michurin was repairing the church after the fire of 1737, and in 1756 it was renewed by D.V. Ukhtomsky. It was under his supervision that a new iconostasis and new murals were made in the interior.

During the preparations for the construction of the Kremlin palace according to the project of Vassily Bazhenov in the early 1700s the house of the clergy was demolished, after which the church was left without a parish and as a result was attached to the Ascension Convent.

It is known that there was a side chapel of St Nicholas the Wonderworker since 1778, located on the south side of the church.

During the Patriotic War of 1812, the church was completely ruined, and by resolution of His Grace Augustine it was to be demolished. However, by decision of Emperor Nicholas I, in 1837 it was restored and re-consecrated.

South panorama of the Kremlin, with the Church of Sts Constantine and HelenChurch of Sts Constantine and Helen, view from the westView from parade ground to the Church of Sts Constantine and Helen

Southern façade of the Church of Sts Constantine and HelenыSouthern façade of the Church of Sts Constantine and HelenWestern façade of the Church of Sts Constantine and Helen

The church kept that appearance until 1928, when, by decision of the new government, it was dismantled due to its extreme dilapidation. It should be said that before the dismantling, the above-ground part of the church was carefully measured by the leading architect-restorer P. Maksimov, and detailed drawings were made according to the measurements.

In 1989, an unremarkable building was erected on the site of the demolished church to house the KGB’s Office concerned with the Protection of the Government. At the same time, the cellars and foundations of the Church of Constantine and Helen were destroyed without any research.