The “upper room” mentioned in the Gospels is a typical name given to the location of the Last Supper of Jesus and His Disciples (Mark 14:15; Luke 22:12). This place, also known as the Cenacle from the Latin word cenaculm, which simply means “upper room,” was adopted from the Latin Vulgate. In the Greek text of the Gospels, the word used to describe the room refers generally to an upper floor of a house, but archaeological research has further illuminated the probable location and architecture of the house where the Last Supper occurred (Liddell et al., A Greek-English Lexicon, 169). The particular site known as the Cenacle, thought to be the location of the Upper Room and Last Supper, is situated near the top of Mount Zion in the southwestern section of ancient Jerusalem. While the evidence for the precise location is largely circumstantial, it has been known since at least the 4th century AD when a church was built by Theodosius I adjacent to the original “Church of the Apostles” on Mount Zion. Earlier texts suggest the ancient tradition of the church going back to the 1st century, as writers mention a Cenacle church on Mount Zion in existence during the time of Emperor Hadrian ca. 130 AD which supposedly originated in a house church of the 1st century—perhaps even the house which contained the Upper Room (Cyril of Jerusalem; Epiphanius, Treatise on Weights and Measures; Itinerarium Egeriae). According to these sources, the building seems to have survived the devastation of 70 AD and continued in use into the Byzantine period, although it was probably abandoned for several years when the Christians temporarily left Jerusalem during the First Judean Revolt against Rome (Eusebius, Ecclesiastical History). The Byzantine church was destroyed by the Persian invasion of 614, rebuilt, destroyed again by the Islamic caliph Al-Hakim in 1099, then rebuilt by the Crusaders in the 12th century before being partially destroyed in 1219. Even if the building identified in the 4th century is not the exact location of the Upper Room, it would have been in the immediate vicinity, and 1st century architectural remains were found underneath the church which verify the presence of a building from the time of Jesus and the Disciples (Pixner, “The Church of the Apostles found on Mount Zion”; Murphey-O’Connor, “The Cenacle and Community: The Background of Acts 2:44-45”). The orientation of the building is toward the Church of the Holy Sepulcher, and a church at that location is depicted on the 4th century Pudenziana mosaic, the 5th century Santa Maria Maggiore mosaic, and the 6th century Madaba map, and the artwork appears to show the ancient house church adjacent to the Byzantine church.
According to the book of Acts, this house, the residence of Mary the mother of John Mark, had a large upper room that could accommodate up to 120 people (Acts 1:13-15, 12:12). The word used in Acts differs from the word used in Luke, as in Acts the language suggests that the room or upper floor had been modified or converted. Perhaps Luke made this distinction because the Upper Room changed from a place temporarily used by Jesus and the Disciples to a place that continued to be used by the early Church, perhaps even designating the upper floor as a “church building” or gathering place. In the 1st century, the upper rooms of Christians in Jerusalem and the rest of the Roman Empire became some of the first “churches” or gathering places for the Church due to the lack of any actual buildings designated for that specific purpose, and the convenient architectural design that allowed many people to gather in one large room, such as the house of Mary in Jerusalem which was large enough for many people to gather (Petersen, “House-Churches in Rome”; Acts 12:12). Because this room could accommodate up to 120 people and the Greek word refers to an entire upper story, it sounds as if the Upper Room would have been a large open space that occupied the entire second or third story of a large house. With the additional description of a gate and a servant attendant, the assumption that the owner was wealthy and the house was large is validated further (Acts 12:13-14). In 1st century Judea, many houses had an upper floor which was used for living space, gathering places, or bedrooms and reached either by a staircase attached to a wall or by a ladder (Botha, “Houses in the World of Jesus”). Large, decorative houses or manors with multiple stories, matching the description of the “Upper Room,” have been discovered in Jerusalem, and particularly in the area of southwest Jerusalem on the Western Hill or Mount Zion, where the main neighborhood of the wealthy was located. In a section of the Jewish Quarter, also referred to by the ancient designation “Herodian Quarter,” the Burnt House was excavated in the 1970s. This house, which dates to the 1st century AD and before the 70 AD destruction of Jerusalem, is a wonderfully preserved house, which belonged to a wealthy 1st century Judean. The mansion included painted wall frescoes, colored mosaic floors, bathtubs, and ritual baths. Slightly to the northwest, in the present day Armenian Quarter, the “house of Caiaphas” on Mount Zion is another example of a 1st century residence appearing to belong to a wealthy priestly family, although its identification with Caiaphas is only tentative. Slightly to the south and just outside the present Old City walls, excavations have discovered remains of a third large mansion from the 1st century. This neighborhood of northwest Jerusalem was at a higher elevation, near Herod’s palace, which became the Praetorium, and had easy access to the Temple, making it a prime location within the city. Based on the remains of similar buildings, the house containing the Upper Room would have been made primarily of limestone, with mosaic floors, plastered walls, which may have been painted, high windows, and probably a bathroom and ritual bath. After the construction of the Byzantine church in the 4th century, which seems to have been an enlargement or remodel of an earlier church that originated with the house containing the Upper Room, the building continued to function as a church for centuries.