The baptistery chapel of the basilica of Moses
(at the time of Bishop Sergius, 597/98)
The mosaic decoration of the new baptistery chapel, situated in the area of the mosaiced room outside the southern wall of the basilica, was completed in 597/8, at the time of bishop Sergius of Madaba and the Abbot Martyrius. This can be read in the medallion inscription close to the polylobed baptismal font.
The composition has as its centre the cross-shaped monolith font which is at the centre of the conch of the new chapel. A row of white tesserae medallions on a black background enclosed within a toothed band of red tesserae surrounds half the font, in the space which separates it from the apsidal splay. Yellow tesserae flowers and leaves together with white tesserae crosses are added in the spaces between the medallions. These medallions were decorated with animals and vegetables as can be deduced from the two surviving medallions where the tail of a bird and a bunch of grapes among leaves and tendrils are well preserved.
The area in relation to the projection of the font is enclosed by two specular medallions on a white background in which we find the dedicatory inscription accompanied on the inside by two heart-shaped leaves and on the outside by two birds facing a vegetable motif.
The area in front of the font, between the font and the closing step, is decorated by a rectangular panel the width of the whole chapel. This panel is enclosed by a meander band of hooked inverted swastikas and double return swastikas together with a band of plain red tesserae on either side. The internal field of the panel is highlighted by five small trees laden with fruit, among which one can recognize pomegranates, pears or prunes and apples, mostly made of yellow tesserae which stand out on the dark and white background of the foliage.
Between the saplings, reaching the height of the trunks which are made up of double or triple superimposed mouldings executed using red, yellow and grey tesserae with the addition of leafed shoots, there were represented, specularly, four birds alternated with two gazelles. These are still recognizable in spite of the damage sustained by the mosaic at the hands of the iconoclasts. The empty spaces caused by the removal of the coloured tesserae forming four of the figures had been roughly restored with larger white tesserae
A single line of vertical flowers had been added in the bordering space, between the panel and the side walls
The nave is decorated with a unique motif. Adjacent and intertwined octagons which form squares and hexagons. These are enclosed by a band consisting of triflids alternated with circles and squares placed diagonally, accompanied by small crosses of white tesserae on a red background. The octagons are formed by lines of flowers forming crosses which highlight the squares which are decorated with a Catherine-wheel motif on a dark background. Flowers, placed at right angles, had been added on the external perimeter to underline the idea of the whole composition being a carpet.
Furthermore the panel is surrounded by a second band made up of lunes, circles and lines of flowers. The entrance to the baptistery in the north wall, which has always been in use, carries a greeting written in a panel of red and yellow tesserae: Peace to all.
The mosaic in the baptistery, in the same way as that in the Theotokos Chapel, attracts one's attention because of the accurate technique used in the laying of the mosaic, the elegance of the whole composition as well as the amount of detail therein. Some of the animals and vegetative motifs used here are to be found also in the Theotokos Chapel as well as in the presbytery of the Church of the Lions at Umm al-Rasas. This leads one to suppose that all there works were performed by mosaicists from the same workshop.