When the Crusaders built their church on the ruins of the Byzantine Hagia Sion, they incorporated into their building the Apostolic Church (the Judeo-Christian synagogue). Formerly, the Apostolic Church had stood outside and next to the Byzantine churches on Mt. Zion.

The above plan shows the excavated archaeological remains of the Crusader church and the rest of the structure that is presumed but not found. In the northwest corner of the building, bottom left, eight pillar and half-pillar foundations and one pillar pedestal were found in excavations. A portion of the western exterior wall including its southern corner, lower right, was discovered during the author’s recent investigations. A part of the foundation of this wall appears in the photo below; it incorporates a Byzantine or Roman column, the flat, round stone near the center in the third course from the top.

The southwestern corner is in exact alignment with the ancient Judeo-Christian synagogue’s southern wall, which is extant to a height of about 12 feet. From this alignment the full length of the southern wall of the Crusader church is projected on the plan. In the southeastern part of the basilica, upper right, the cenacle building from Crusader times still stands, as do some of the walls from the first-century Apostolic Church, which now enclose the pseudo-tomb of David. Among the Crusader remains is the upper half of a column that once extended from the ground floor up to the ceiling of the church; today it stands just outside the cenacle building, next to the entrance to the upper room.

Above the remaining walls of the Church of the Apostles, the Crusaders built the Chapel of the Holy Spirit, to commemorate the Pentecost event (plan, below).

In front of the niche in the pseudo-tomb of David, the Crusaders placed a large stone cenotaph, decorated with rosettes (below), and in the room next to the pseudo-tomb of David, the Crusaders commemorated the place where Christ washed his disciples’ feet.

Above that room they built the Chamber of the Mysteries, which is today called the “cenacle” (below), marking the Upper Room where the apostles returned after witnessing Christ’s ascension into heaven (Acts 1:1–13), and where Jesus ate the Last Supper.

The canopy in the background at center, erected by the Crusaders and modified slightly by the Moslems, covers the stairwell by which the room was formerly entered. Its near pillar bears a capital (see front cover) that is decorated with representations of pelicans with folded wings. On each side, a central pelican feeds two young on its own blood. This reflects the ancient belief, recorded by the Roman naturalist Pliny the Elder (23–79 A.D.) in his Natural History, that pelicans would, if necessary, feed their young with their own blood even to the point of sacrificing their life. The legend became a symbol of Christ giving his own blood in the Eucharist (the communion experience) and of his sacrifice on the cross. The central pelican stands upon a death-mask symbolizing the sacrifice. Until ten years ago the pelican capitals were unseen beneath a layer of plaster applied sometime after the Crusader period. Grapes, a Eucharist symbol for wine, decorate the architrave of the cenacle.