The Carolingian rood-screen and the porta aurea of the monastery church of St. Alban (787-805) near Mainz

Abstract

Richulf, Archbishop of Mainz (787-813) had the three-aisled basilica of the Imperial monastery of St. Alban built following the wish and with the support of Charlemagne. This sacred building consecrated in 805 in
the south of Mainz belonged to the largest churches of its time and to the most important places of assembly within the Empire. It was destroyed in 1552 and completely demolished in 1632. According to common opinion the excavations of 1907 to 1911 revealed no significant traces of the Carolingian interior. How ever, there are two outstanding archaeological finds which even today still allow one to recognise the intended constructional support of the ruler. Walled up in the Gothic choir was a 114 cm high rood-screen pillar of high-quality Jura limestone which is falsely attributed to the early 12th century. This pillar, which on its concave,
front surface bears a shallow engraved Roman crossed cymatium, has obviously been worked out of a Roman gable-stone and is, therefore, a spoil. On the open face is the flat relief of a scroll with round, interwoven, opposite half-palmettes, which stand out as a light, smooth surface against the light red back - ground in the chamfered indentations. This is a typical scroll decoration of the 8th or early 9th century, which at that time was only common in northern Italy and the eastern Adriatic coast.  Therefore, the extraordinary rood pillar was created by a stonemason from the South. As the rectangular upper surface remained unworked and, thus, supported something, the pillar should have been part of a very  expensive, typical Mediterra nean ‘pillar-rood’ with a horizontal, decorated beam (trabes) and at least one entrance arch. The monastery church of St. Alban in Mainz also possessed a porta aurea, i. e. one of the rare and extremely valuable doors of cast bronze. This must be identical to the early Roman, pierced bronze door which, until its chance discovery in the neighbouring Alban Entrenchment in 1845, had remained completely intact. Once part of a public building in Roman Mogontiacum, it would as the  result of its high material value have been melted down during the Migration Period at the latest. Thus, one can assume that this deco rated bronze door, cast in the area of Brescia, belonged to those antiques which  Charlemagne had brought back from Italy, in order to adorn his new buildings with them. Because of their venerable age, they would not have been simply discarded centuries later, but in times of danger, e. g. prior to the approa - ching troops of Margrave Albrecht Alkibiades in 1552, would have been purposely hidden.