San Giovanni in Laterano Baptistery – a water-filled cradle of Christianity

San Giovanni Baptistery, ancient bath decorating the baptismal pool

San Giovanni Baptistery, ancient bath decorating the baptismal pool

The significance of baptism during the first centuries of crystallization of the new religion was immense, since it symbolized a second coming into the world without the blemish of sin, washed away during the ceremony with the usage of water. The newly baptized was accepted into a commune of co-religionists and only then could he participate in the liturgy of the Holy Mass. In Rome baptism was initially performed by the bishop of Rome himself (the pope), and the whole ceremony was conducted in a grand atmosphere, as it was supposed to remind the faithful about the baptism of Christ in Jordan, but also bind them emotionally to this very important religious act.
San Giovanni Baptistery, ancient bath decorating the baptismal pool
San Giovanni Baptistery, building from the V century
Frieze adorning the San Giovanni Baptistery with insignia of Pope Alexander VII (1657)
San Giovanni Baptistery next to the Basilica of San Giovanni in Laterano
View of the San Giovanni Baptistery in the XVI century – drawing by A. Lafrery, according to R. Krautheimer Rom. Schicksal einer Stadt
San Giovanni Baptistery, original, southern enterance into the building vestibule
San Giovanni Baptistery, capitol of the baptistery vestibule from the times of Constantine
San Giovanni Baptistery, painting decoration – the life of St. John the Baptist, author: Andrea Sacchi, view of the dome
San Giovanni Baptistery, porphyry columns from the times of Emperor Constantine
San Giovanni Baptistery, fresco above the enterance to the Chapel of St. John the Baptist, Constantine’s Victory over Maxentius, A. Camassei, XVII century
San Giovanni Baptistery, Miracle of the Holy Cross, Giacinto Gimignani (17th century)
San Giovanni Baptistery, Triumphant Entry of Constantine into Rome, A. Camassei, XVII century
San Giovanni Baptistery, Council of Nicaea and the Burning of Arian books, fresco by Carlo Mannoni, XVII century
San Giovanni Baptistery, outer view of the Chapel of St. John the Baptist
San Giovanni Baptistery, Chapel of St. John the Baptist from the V century, reconstructed in the XVIII century
San Giovanni Baptistery, figure of St. John the Baptist, Luigi Valadier
San Giovanni Baptistery, Chapel of St. John the Evangelist, vault, mosaics from the V century
San Giovanni Baptistery, Chapel of St. John the Evangelist, vault, mosaics from the V century, central part depicting the Lamb of God
Chapel of St. John the Evangelist, vault, mosaics from the V century, fragment
San Giovanni Baptistery, Chapel of Justina and Cyprian, mosaics from the V century
San Giovanni Baptistery, baroque angels adorning a niche in the Chapel of SS. Justina and Cyprian
San Giovanni Baptistery, Chapel of Justina and Cyprian, mosaics from the V century
San Giovanni Baptistery, Chapel of SS. Justina and Cyprian, mosaics from the V century, fragment
San Giovanni Baptistery, Chapel of SS. Rufina and Secunda, decorations from the XVIII century
San Giovanni Baptistery, Chapel of SS. Rufina and Secunda, (old vestibule), tombstone monument of Niccolò Lercari, Tommaso Righi, middle XVIII century
Giovanni Baptistery, (old vestibule), tombstone monument of Cardinal Alessandro Borgia, Tommaso Righi, 1767
San Giovanni Baptistery, old vestibule, remains of a wall decoration (opus sectile) from the V century
San Giovanni Baptistery, old vestibule, column and base of an ancient column
San Giovanni Baptistery, old baptistery vestibule, ceiling from the XVIII century
San Giovanni Baptistery, marble slab depicting the Crucifixion, old vestibule
Chapel of SS. Rufina and Secunda, tombstone monument of Niccolò Maria Lercari, Tommaso Righi, mid XVIII century
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus – VI century, mosaic decorations – VII century
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, mosaic on the chapel, triumphal arch from the VII century, saints Paulinian, Attelius, Asterius, Anastasius
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, apse, mosaic decorations from the VII century
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, Maria surrounded by SS. Paul an d Peter as well as St. John the Evangelist (on the left)
San Giovanni Baptistery, Chapel of SS. Venantius and Domnius, mosaics on the apse and rainbow – VII century
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, mosaic on the triumphal arch from the VII century, - saints Maurus, Septimius, Antiochianus, Gaianus
Chapel of SS. Venantius and Domnius, decoration of the triumphal arch w representation of Dalmatian saints (Paulinian, Attelius and Asterius)
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, decorations of the rainbow, symbolic representation of the evangelists (SS. Luke and John)
San Giovanni Baptistery, Chapel of St. Venantius, main altar, Carlo Rainaldi
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, tabernacle from 1482, workshop of Andrea Bregno
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus, tombstone of Canon Francesco Adriano Ceva, design by Carlo Rainaldi, execution by Giuliano Finelli
San Giovanni Baptistery, Chapel of SS. Venantius and Domnius, tombstone of Cardinal Adriano Ceva, design – Carlo Rainaldi, execution – Giuliano Finelli
San Giovanni Baptistery, Chapel of SS. Venantius and Dominus
The significance of baptism during the first centuries of crystallization of the new religion was immense, since it symbolized a second coming into the world without the blemish of sin, washed away during the ceremony with the usage of water. The newly baptized was accepted into a commune of co-religionists and only then could he participate in the liturgy of the Holy Mass. In Rome baptism was initially performed by the bishop of Rome himself (the pope), and the whole ceremony was conducted in a grand atmosphere, as it was supposed to remind the faithful about the baptism of Christ in Jordan, but also bind them emotionally to this very important religious act.

One of the most important Christian structures – the Lateran baptistery, also known as the baptistery of St. John at the Font (San Giovanni in Fonte) is found right next to the Basilica of St. John in Lateran (San Giovanni in Laterano).  It constituted one of the most important parts of the whole Lateran complex, which also featured the plaza with the Lateran Obelisk, the Apostolic Palace of the Lateran, the Sancta Sanctorum Chapel and the Holy Stairs (Scala Santa) leading to it. The baptistery, just as the basilica, was funded by the Emperor Constantine the Great at the beginning of the IV century. It is therefore, one of the earliest Christian structures, as well as the oldest place of baptism known today. Based on its design, other baptisteries with central arrangement, based on a circle or octagon will later be constructed all over the Christian world all the way up to the Middle Ages, when the ceremony of baptism through immersion of the whole body will no longer be mandatory, while due to the common habit of baptizing babies, baptismal fonts standing inside churches will become popular.

Baptism took place during Easter time, at night from Holy Saturday to Easter Sunday. A candidate to be baptized first took part in preparation for the sacrament in the Basilica of St. John. Then he walked to the baptistery, took of his robes and entered the baptismal pool naked, where he immersed himself in water three times. Then he entered a neighboring room (which would later become the Chapel of St. Venantius), where he received anointing. As a sign of receiving the sacrament he put on a white tunic (a symbol of purity and a rebirth of the purified soul), which he wore the following week. The ceremony concluded with a second entry to the basilica in Lateran, where the newly baptized was able to, for the first time, participate in the Holy Mass.



The appearance of this first Constantinian baptistery is known to us only through a description kept in Liber Pontificalis, a very significant document for research regarding early-Christian times. During antiquity its location was a place, where a Roman nymphaeum stood spouting with water, which belonged to the residential complex of the Laterani family. After Constantine took over the family’s estate, the structure was given over to Christian hierarchs in order to adapt it to the function of baptistery and was richly furnished. Legend says that the emperor himself was baptized here, at the hands of Pope Sylvester I, but it strays from the truth, since Constantine was indeed baptized, but historians unanimously confirm that it was at the end of his life and under circumstances unknown to us – probably on his deathbed in 337 A.D. in Achyron near Nicomedia.

Initially the baptistery had the form of a circle. The monumental, porphyry columns, which decorate the interior and the vestibule of the structure, were brought from Africa. The whole was embellished with mosaics, marble floors, as well as silver liturgical vessels and other decorative objects (Lamb of God in gold, images of Christ and John the Baptist in silver). They were accompanied by silver deer spouting water from their mouths, placed on the edges of the pool – they symbolized thirsty pagan souls, seeking to reach the source, meaning true faith.

It was not until a century later, in the V century, that in place of the round structure, which most definitely suffered during subsequent catastrophes ravaging the city, Pope Sixtus III ordered the construction of the octagonal structure we know today. The number eight as a repeating motif of the interior, was not chosen by accident – on the eighth day after his resurrection, Christ appeared to his disciples, which was a great symbol of baptism as a rebirth into new life.

Today we enter the baptistery from a busy street on the north side (near a side entrance to the Basilica of St. John), but in the past it was entered through a door on the other side. The entryway was preceded by a vestibule with beautiful basalt columns and elaborately shaped capitals.


The crude brick structure has not changed its internal form since the V century, besides a decorative cornice which immediately draws our attention. It is decorated with the insignia of the well-known Chigi family from which Pope
Alexander VII came, one of the patrons of the baptistery, who funded its modernizations which took place mainly in the XVII century. The author of these decorations was not just anybody, but the great Francesco Borromini himself.

Entering through the present-day entrance into the interior, an unaware traveler may be disappointed – the oldest baptistery is nothing like early-Christian constructions. He is greeted by Baroque paintings depicting the deeds of the founder of the holy sanctuary – the Emperor Constantine. They were created during the modernization, between the years 1580 and 1661 and they are a joint work of well-known painters of that time. It is worth to mention the frescos The Destruction of Pagan Idols (Carlo Maratti) or the painting The Vision of the Cross by Constantine the Great (Giacinto Gimignani). 

Nevertheless, even here we will notice signs of antiquity. The baptism pool is still surrounded by the aforementioned circle of ancient, basalt columns bearing the architrave, which with the aid of narrow stanchions supports the dome with decorations, once again dating back to the XVII century (contemporary copies).

A description written by the erudite Onofrio Panvinio in the middle of the XVI century, so one hundered years prior to the general modernization of the baptistery which led to a complete change in its decorations, speaks of a cradled vault in part of the ambulatory, of mosaics found there, as well as of walls richly decorated with marble slabs (opus sectile), finally of ornamental motifs. We can see what they looked like walking over to the old vestibule, where they remained in residual form on the north wall.

The whole was completed by a dome, accentuating and heightening the main part of the structure, which was the round baptism pool.Besides the Baroque paintings which densely fill the hall, we can also see the heraldic elements of subsequent popes, who contributed to the modern modernization: a winged dragon of Gregory XIII, during whose pontificate the wooden vault of the Chapel of Venantius was also completed; next to which we can see bees from the coat of arms of the Barberini family which indicates Pope Urban VIII, as well as a dove with an olive branch – the element of the coat of arms of Innocent X. The final restoration works in the baptistery were completed during the pontificate of Paul VI, in the sixties of the XX century, which is depicted by his insignia visible on the floor of the Chapel of St. Venantius.



A seeker of early-Christian relics however, will not leave the baptistery disappointed, even if there is a spirit of Baroque floating about in the main part. This is thanks to the chapels (oratories), which were gradually added to the structure, in this way creating the first places of cult of  St. Johns – the Baptist and the Evangelist. Three of them were created during the pontificate of  Pope
Hilarius (461-468) – one in which the relics of the Holy Cross (Sant Croce) were kept, was completely deconstructed in the XVI century, however the other two still exist.  They kept their original interior, but also more.

The first one (on the western side) is devoted to St. John the Baptist. The doors leading to it were a part of the deconstructed baths of Emperor Caracalla. However, we will not find the original mosaics on the vault, since the chapel was completely reconstructed in the XVIII century. The only interesting object is a statue of St. John the Baptist made of bronze, found in the altar, the work of Luigi Valadier (1726-1785), whose name is known mainly because of his son – Giuseppe Valadier, a valued Roman architect active in the XIX century.

On the opposite side is the chapel devoted to St. John the Evangelist. Its most important and worthy of utmost attention decoration consists of well-preserved mosaics from the V century.  Modest, simple in form, in its central part they show the Lamb of God, in other parts there are flower garlands as well as birds adoring vases with pomegranate seeds. These seeds symbolized eternal life, while the aforementioned birds – the four elements: ducks – water, partridges – earth, pigeons – air, while colorful creatures reminiscent of the legendary phoenixes were of course a symbol of fire.

However, some of the most interesting chapels are two others, next to the main hall. One was adapted to a place of cult from the old vestibule, embellished with the aforementioned porphyry columns with composite capitals and richly decorated bases, which we have already seen on the external side of the baptistery. The chapel is oval in shape and its right and left niches were in the past embellished by, presently kept in only one niche, marvelous early-Christian mosaics from the V century. In the XI century both apses were converted into chapels devoted to early-Christian martyrs. The one on the left (looking from the baptistery) is devoted to Justina and Cyprian, martyrs from Syria. It is decorated with a mosaic showing a coil of acanthus spread over a dark azure background, which is supplemented by depictions of doves, the Lamb of God and crosses. It is a great example of assimilating late-antique symbols of fertility and life which were enriched by Christian motifs. The mosaics are, along with those found in the neighboring chapel of St. John the Evangelist, as well as those found in the Church of Santa Constanza, some of the first in Rome, early-Christian ornamental decorations. The opposite apse of the chapel devoted to Rufina and Secunda was similarly decorated, however, its mosaics were unfortunately destroyed. They were replaced in the XVIII century by the stucco decorations visible today. Another antique element of the vestibule is the aforementioned and partially maintained on the north wall marble slabs with ornamental patterns, which in the past decorated the whole area of the vestibule and also the baptistery itself. Tombstone statues found at both apses are directed towards the altars in a gesture of prayer and devotion. These statues represent two members of the Lercari family (Niccolò and Niccolò Maria), who in the middle of the XVIII century were the generous patrons of modernization works, transforming the interior in the new spirit of rococo. This deed ensured their significant place of eternal rest. Their author was the Rome-based, but virtually unknown in the city, sculptor and architect who is famous thanks to works completed in the far reaches of the Polish-Lithuanian Commonwealth – Tommaso Righi. From an artistic point of view another fully successful tombstone statue found in the chapel, completed by the same artist, commemorates Cardinal Alessandro Borgia, representing him (which seems a bit odd for a clergyman) in the company of the allegory of Fame. The  cardinal was given this dignified place of burial, also thanks to his funds which he used to restore and modernize the baptistery.

However, the greatest mosaic decorations, this time from the VII century, completed in a separate Byzantine style, decorate another chapel devoted to St. Venantius (Venanzio) and Domnius – two Dalmatian martyrs from the VI century. On a shining with gold background of the apse in the upper part a representation of Christ among angels was placed; in the lower part it is supplemented by a row of saints with the Virgin Mary raising her hands in a gesture of adoration, being accompanied on both sides by two most important Roman saints – Peter and Paul, while in the second row we find two patrons of the nearby basilica – John the Baptist and John the Evangelist, and then the aforementioned saints – Venantius and Domnius. In the two outermost figures we can recognize the initiators and funders of these decorations – Pope John IV (with a model of the chapel) and his successor – Pope Theodore, the two Roman bishops from mid-VII century. On the left and right side of a rainbow we can notice the figures of other Dalmatian martyrs, whose remains were brought to Rome by Pope John IV and placed in the altar of this very chapel. We can ask ourselves why the attention provided to all these Dalmatian martyrs. Well, John IV himself came from the area of present-day Croatia. His wish was to commemorate martyrs of Spalato (present-day Split), whose places of burial were threatened by the invading Slavic tribes. The pope, as it was said, brought their relics to Rome, along with other martyrs from the region, whose figures we can recognize on both sides of the rainbow (on the left: Paulinian, Attelius, Asterius, Anastasius while on the right: Maurus, Septimius, Antiochianus, Gaianus). pics. As it is fit for apse decorations, there must have been room for the symbols of four Evangelists visible at the top, as well as for the two most important towns – Bethlehem and Jerusalem, which we can see in the upper part of the rainbow.



Unfortunately, these beautiful mosaics are to a large extent covered by an XVII century Baroque altar, completed by
Carlo Rainaldi. Its main element is a medieval fresco depicting the Madonna and Child. Rinaldi was also the designer of two tombstones of cardinals (Francesco and Francesco Adriano Ceva), flanking the altar, which he entrusted to another highly regarded in Rome artist, Giuliano Finelli. Another thing worthy of our attention is the early-Renaissance tabernacle, embedded into a wall, decorated with subtle figures of angels, created at the end of the XV century in the workshop of the highly valued in Rome sculptor Andrea Bregno.

The baptistery today is visited by only few tourists and pilgrims, despite the fact that, it would seem to be, one of the most important places for Christians, exuding an amazing aura of – peace, reflectiveness and nostalgia. It reveals the beginnings of the religion which was exotic and incomprehensible to ancient Romans, taking us to times, when being a Christian was not an obvious fact acquired at birth (as it is today), but a slow-moving process, which the followers of Christ underwent with determination and joy, since immersing oneself in water, meant the beginning of a completely new life.