Today’s icon type is uncommon and easily misidentified. To make matters more difficult, it is a very variable type. Examples can look quite different, from simple to extremely complex.
Let’s begin near the simple end with this fine example:

Here is how misidentification of this type usually happens. One looks at the unfamiliar icon and is a bit puzzled. Seeing the figure standing at center base, one may recall seeing him before. Where? In icons of the Pokrov, the “Protection of the Mother of God.” Pokrov icons are quite common. Here is one:

Now it is correct that the standing fellow in red is the same saint in both icons. The mistake one may easily make from this point is to think that because they are the same saint in much the same position, today’s icon must be a Pokrov variant of some kind.
It is not. The only similarities are the guy in red on the platform — who is Romanos the Melodist — and the domes signifying that the setting is a church. Other than that, Mary — an essential element in Pokrov icons — is notably absent.
Further, in Pokrov icons, Romanos commonly holds a scroll with a Church Slavic inscription reading: “Today the Virgin stands in the Church ….”
However, that is not at all the scroll inscription Romanos is holding in today’s icon, which reads:
“A saving tree has appeared today from the bowels of the earth, which in the church …”

It is the beginning of the Kontakion of the Presanctification, Voice 8, from the Forefeast of the Exaltation of the Honorable and Life-giving Cross of the Lord;
“A saving tree has appeared today from the bowels of the earth, which in the church the bishop honorably lifts up in his hands. The universe, worshiping, kisses it with fear. Save us O Lord.”
If we look at the scroll inscription held by the monk on the left, we see that it is just a slight variant of this Troparion of the Renewal of the Jerusalem Church:
Якоже вышния тверди благолепие и нижнюю споказал еси красоту святаго селения славы Твоея Господи утверди сие во век века и приими наша в нем непрестанно приносимая Тебе моления, Богородицею, всех Животе и Воскресение.
“Like the splendor of the heavenly firmament, you have revealed on earth the beauty of the holy temple of Your glory, O Lord! Establish it forever and ever, and accept, through the intercessions of the Birthgiver of God, our prayers, unceasingly offered to you in it, the Life and Resurrection“
If we put all of this together, we may correctly conclude that today’s image is an icon of the “Renewal of the Temple of the Resurrection of Christ in Jerusalem” (Обновление храма Воскресения Христова в Иерусалиме).
That is an annual commemoration in the Liturgical calendar of the Russian Orthodox Church, as we find in the Svodnuiy Ikonopisnuiy Podlinnik, under September 13th, as the Obnovlenie khrama Voskreseniya Khristova, izhe vo Ierusalimye — “The Renewal of the Temple of the Resurrection of Christ, which is at Jerusalem.”

Icons of this type may be traced back to the 1500s.
Of course if we had looked at the icon really closely at the beginning, we would have seen a rather dim inscription running atop the domes of the church. Here is the beginning of it:

Yes, the title of the icon is there; it is just rather difficult to make out, and written so small, it does not look much like usual, larger icon title inscriptions.. That is a caution to us to pay attention to small details. Even though some words are too faint to decipher, we can see the word ХРАМА (Khrama/Temple) clearly, and following it the beginning of ВОСКРЕСЕНИЯ (Resurrection) — so ” …Church of the Resurrection …”
Now to return to Romanos. Why does he hold a scroll talking about the “saving tree,” a Kontakion from the Forefeast of the Exaltation/Elevation of the Cross? It is because the Forefeast of the Elevation of the Cross happens on the same day as the commemoration of the Renewal of the Church of the Resurrection in Jerusalem — September 13th.
Now let’s look at the various parts of the icon:

At the top, we see the liturgy being celebrated in the church. The main figure with his hands elevating a cross is James, the brother of Jesus — by tradition the first bishop of the Jerusalem Church. With him are other clerics. Those with halos are John Chrysostom, Gregory the Theologian, and Basil the Great. Those without are two deacons. Before them is the diskos bearing the “Lamb of God” in the form of the child Jesus, representing the Eucharistic bread.
Below, as we have seen, is Romanos the Melodist. To his left is a monk apparently intended to be Cosmas of Maiuma, also known as Cosmas the Melodist.

At lower right is a depiction of the Resurrection, seen as the Descent to Hades. It is included because the subject of this icon is the Church of the Resurrection.
You will recall that I began by saying the Renewal of the Temple of the Resurrection is a very variable type. Well, you are about to see just how variable. Examples can look so completely different that one would hardly know it is the same subject.
Here is one from the 18th century. Its title — written at the top — is “Renewal of the Temple of the Resurrection of Christ our Lord.” In the three ovals near the top are scenes of the Crucifixion, the Resurrection, and the Transfiguration. Below, between two pillars, is an icon of Mary, and below that a group of clerics with the large central figure identified by name inscription as “Holy Patriarch Nikifor [Nicephorus].” By the left pillar stands “Holy Emperor Constantine,” and by the right pillar, “Holy Empress Elena [Helena]”

Bearing a bit more resemblance to today’s main icon, in that it has the depiction of the liturgy with the Lamb of God, and the Descent to Hades, is this late 16th-early 17th century restored example from the Stroganov School. It is the upper half of a two part icon, with the “Praise of the Most Holy Mother of God” depicted in the lower half omitted here. Among the other scenes it includes are the Crucifixion and the Creation of Man, The Doubting of Thomas, the Old Testament Sacrifice in the Temple of Solomon, the Preparation of the Throne, and a group of angels.

There are versions of the type that are even more complex, such as this example from the latter part of the 17th century:

So now you have been cautioned about the great variability of this type. But what exactly does the the “Renewal of the Temple of the Resurrection of Christ in Jerusalem” commemorate?
It commemorates the Consecration of the Church of the Resurrection in Jerusalem on September 13, 335, which by tradition was built at the order of Empress Helena on the site where she supposedly discovered the “True Cross” of Jesus — the location of the Crucifixion and the Resurrection of Jesus. Today the Church of the Resurrection is more commonly known as the Church of the Holy Sepulchre.
What the Russians call the обновление / obnovlenie (“renewal,” “restoration”) of the Church, the Greeks call the ἐγκαίνια / engkainia, meaning “dedication” “inauguration,” or “renewal” (of religious services). Icons of this type, however, are primarily Russian.

