By Patrick Hunt –
Aachen Cathedral (also known in German as the Kaiserdom) is one of the most important monuments in the Early Medieval World, begun circa. 796, and symbolically identified with the end of the Dark Ages when literacy was finally resurgent in the Carolingian Age. Charlemagne built Aachen’s palatine church and adjacent palace as Einhard, his posthumous biographer, affirms:
“Hence it was that he built his palace at Aachen, and lived there constantly during his latter years until his death…He built the beautiful basilica at Aachen, which he adorned with gold and silver and lamps, and with rails and doors of solid brass. He had the columns and marbles for this structure brought from Rome and Ravenna, for he could not find such as were suitable elsewhere. ” 
Revisiting in March 2019, the author spent more time than previously especially studying the throne identified with Charlemagne, the Karlsthron in German, as well as named the Aachener Königsthron and identified with coronation of German emperors until 1531. Whether it was constructed before or after Charlemagne’s own imperial coronation in Old St. Peter’s Basilica of Rome in 800 by Pope Leo III is uncertain. Whether he could have been re-crowned in this throne later in his reign subsequent to 796 as King or Imperator of the Franks is also unknown.
Constructed of four simple cream-hued marble slabs joined by bronze straps or clamps (fig. 1 above), its provenance and history are much conflated by legend rather than known facts, but even some of the conjectural history is not only fascinating but highly relevant to Charlemagne himself and subsequent imperial authority. Aachen Palatine Cathedral’s upper gallery (west side) is approached by a staircase from the ground level, and there the throne has its private location in the hexagonal basilica – built and decorated in Byzantine style as the architectural canons of the Carolingian Era demanded. While now somewhat stripped bare of accouterments, including the wooden seat likely covered in fabric, the throne is elevated on a limestone platform and fitted with six marble steps (derived from quartered columns) that is likely also an allegory of biblical Solomon’s throne – approached by six steps as I Kings 10:18-19 NRSV states: “The king [Solomon] also made a great ivory throne, and overlaid it with the finest gold. The throne had six steps. The top of the throne was rounded in the back…” Although a clear difference is that Solomon’s throne was said to be made of ivory and covered in gold in this biblical literary account, Charlemagne’s is marble, which important distinction will be discussed in following paragraphs as this marble is legendary and possibly more “precious” than ivory. Like Solomon’s, this throne has a rounded back. Note the circa 1360 Medieval image below of King Solomon on his throne from the Speculum Darmstadt ms 2505 19r Westfalen (Universitäts- und Landesbibliothek Darmstadt) with six steps and rounded back (is this medieval depiction derived from the Karlsthron in Aachen or the description from I Kings 10:19? (fig. 2 below). The Latin below the illumination declares it as Thronus Solomonis.
While it would have necessary to add a lowest black marble step to make six steps to solidify an allusion to King Solomon – this deliberation is emphasized by the fact that five are pale marble and one is black marble – the symbolic yet visceral connection to Solomon as the richest and wisest ruler of biblical history would have only further elevated the legend of Charlemagne.
A narrow interior hollow space under the Karlsthron’s marble slabs is polished by many visitors – including the most distinguished royalty of Europe – crawling through over a millennium, although now chained off from the public who can walk around the throne.
The throne sits on an original platform (fig. 3 below) of colored decorative stones in opus sectile historically connected to Roman Imperium. Mostly identified with Roman emperors like Trajan and Hadrian at Rome’s zenith in the early second century CE, these semiprecious and expensive stones are rarely found together except in the most important Roman buildings like the Pantheon in Rome (hence Einhard’s above comment in Vita Caroli Magni 26 that stones for the church were brought from Rome and Ravenna). These Karlsthron platform opus sectile decorative stones are: a) Imperial Porphyry (or Porfido Rosso) (purple) from Mons Porphyrites or Gebel Dokhan in Egypt – the most expensive stone in Diocletian’s Price Edict in 301 CE; b) Lapis Lacedaemonius (or Porfido Verde), Spartan Green Porphyry (green with phenocrysts and sometimes bearing even amethyst crystals); c) Giallo Numidiana (or Giallo Antico), Royal Carthaginian marble from Mt. Chemtou in Tunisia in what was Ancient Punic Carthage (cream yellow with burgundy streaked intrusions); d) Docimian Pavonozetto or “Peacock” Marble from Asia Minor (white with purple streaked intrusion; and e) Granito Bigio, a gray granite possibly from a yet-unknown source.  All these Roman imperial stones are found in the Hadrianic Pantheon – the Porfido verde banded on the wall rather than on the pavement – circa 125, (fig. 4), unlikely to be coincidental given Charlemagne’s status as new Imperator Romanorum (did his court acquire these stones in 800 during his coronation journey?).
The six marble steps on the throne platform (fig. 5 below) – which faces east toward the basilica interior, a possibly important symbolic feature identifying the relative direction of Jerusalem – are curved on the underside and four of which were clearly carved from a quartered column (or columns) most likely Roman in origin; although the column pieces like the marble slabs could be from the Church of the Holy Sepulcher in an earlier phase between periodic destructions and rebuilding from 335 onward. While legend has at some time connected the marble steps to Pilate’s Roman court in Jerusalem, it is at present impossible to prove such a legend since the Praetorium court (whether Herod’s Palace or Antonia Fortress – most archaeologists favor Herod’s Palace) is long gone since around 70 CE with Jerusalem’s destruction by Rome. Possible marble provenance will be discussed again in following paragraphs.
Perhaps the most intriguing questions about Charlemagne’s Throne concern the origin of the plain marble slabs. Tradition and even modern scholarship maintains they are from the Church of the Holy Sepulcher of Jerusalem. This remains unproven but the symbolism is profound even if the marble is not truly from Jerusalem. A first caveat is that marble is not found in Israel even if local Cenomanian Limestone can be fairly highly polished, so if the throne slabs are marble, the source must come from the Hellenistic or Roman occupations of Jerusalem. Tradition – with fairly consistent documentation – holds that Helena, mother of Constantine, established the original Church of the Holy Sepulcher on or adjacent to the Golgotha Crucifixion site in late 335 with the help of Bishop Eusebius of Caesarea and Bishop Macarius of Jerusalem. So any stone remnants from that Golgotha association would be truly sacred to Christendom. Proving this physical connection is immensely difficult given the vicissitudes of destruction on the site over subsequent millennia. What stone material was used in the 4th c. building is problematic. Emperor Hadrian in renaming Jerusalem as Aelia Capitolina after his family name (Aelius) had built a temple to Jupiter or Venus circa 135 CE over Golgotha hill and filled in the quarry. Presumably marble would have been used for such Roman temple construction, so that Roman marble material may be the source. Much subsequent damage prior to Charlemagne in the interim between the 4th and late 8th centuries could account for reused Roman rubble reclaimed by the Byzantine Orthodox prelates, although Helena could have obtained marble fragments from either or both Eusebius or Macarius since Caesarea and Jerusalem had ample Roman structures of marble.
The above Madaba Mosaic Map of the 6th century CE (fig. 6) definitely depicts the Church of the Holy Sepulcher centered on Jerusalem’s west side facing east to the Cardo Maximus with its Rotunda dome. By this time the Christian site comprised at least three structures: the Martyrium basilica, the colonnaded Atrium Triportico and the Anastasis Rotunda (as mentioned, the last of which architecture appears to be the westernmost unit on the Madaba Map depiction). So the church was recognizably intact from the time of Helena until at least the mid-6th c., although fire destroyed much of Jerusalem ostensibly including the church when the Persian Sassanid King Khosrau II invaded in 614 CE. The church was documented as rebuilt in 630 by the Byzantine Emperor Heraclius, although again suffering severe damage by earthquake in 746, after which point the Carolingians would not have likely easily obtained any such fragments as to be carefully provenance and ultimately brought to Aachen during the building of its cathedral under Charlemagne. Essentially from even before the Carolingian Period until the Crusades (long after Charlemagne), Jerusalem was greatly under the control of Islam and the marble materials would not be so easily obtained as during the earliest period of Constantine and Helena.
Many related questions about the marble slabs are unanswerable but nonetheless relevant for symbolic reasons. If the Karlsthron material is indeed Roman marble, does it come from Hadrian’s temple over the filled in site, then procured as rubble from the visit of Helena? Was the previous Roman rubble material including marble taken to Rome under Helena’s reliquary search (including fragments of the “True Cross”) or later to Ravenna and obtained by Charlemagne during his coronation visit in 800? (fig. 7 below). Constantine had already ordered the Hadrianic Capitolinus removed from what had been Golgotha in 327 so that Roman rubble – or was it too desecrated? – was available for the building of the Church of the Holy Sepulcher and pragmatics often held sway in reusing old stone rather than quarrying new stone; geologic indigenous marble was as mentioned not found in Palestine in any case. Eusebius (Life of Constantine 26-27) notes the overlying Roman rubble was removed under Constantine’s orders in the search for the Tomb of Jesus; following this, Eusebius relates how Constantine commanded the building of the Church of the Holy Sepulcher with polished stone and adornments (Life of Constantine 30-32), no doubt also importing new marble. On the one hand, it seems unlikely the Byzantine religious powers would let slip from their possession marbles perceived as possible relics of the Roman crucifixion. One of the considerable problems with this scenario of moving rubble marble to Rome is that Constantine had already moved his capital to Constantinople by 330, so why would the marble go to Italy – like coals to Newcastle – instead of Constantinople? On the other hand, Justinian’s building program in Ravenna, however, could explain such a transfer to Italy around 540. Ravenna was the capitol of the Western Roman Empire from 402-76, then the Ostrogoth capitol until 540 when Byzantium conquered it, and remained a Byzantine exarchate even after the Langobards came, although the Langobards were defeated by Charlemagne in 774. The partial rebuilding of Christian Rome after the Ostrogoths could suggest these Roman rubble slabs – perceived as relics from Jerusalem – could then go to Rome.
True or not, another fascinating feature on the south throne slab is the incised game known by the Romans as merellus and later as Nine Men’s Morris (fig. 8). Merellus Glass game pieces (or merella) are prolific – the author has excavated quite a few even from obscure remote Roman sites such as the high altitude Roman mansio below Summus Poeninus in the Pennine Alps (Great St. Bernard Pass) (fig 9). 
Perhaps vitally important to Charlemagne and his artists, the Roman merellus game inscribed on the Karlsthron might have been interpreted as the very spot – however unlikely – where Roman soldiers gambled for the garments Jesus possessed that the gospels note (e.g. Matthew 27:35) were divided by throwing game pieces. These marble slabs would then be even more important relics if thus connected, however dubious in actual fact (pious onlookers could point out: “Look, here is where our Lord’s very garments were divided under the Cross”). Would Rome’s and/or Ravenna’s prelates offer these very same marble spolia fragments to Charlemagne in 800 to solidify his being Imperator Romanorum with a spiritually-invested Christlike kingship? Coronation on the Throne of Charlemagne for subsequent rulers was necessarily “touching” and being grounded by such relics.  Again, as these provenance questions cannot be easily answered and so while much conjecture cannot really be proven, it is critical to remember that perception so often transcended fact and could be more important: it is the symbolic nature of such “relics” that provide Christological propaganda and imperial power to the builders and purveyors of such Carolingian legend, something Charlemagne would have greatly appreciated, with the powerful relics to bolster his very throne.
 Einhard, Vita Caroli Magni 22, 26
 Patrick Hunt. “Pantheon” in Encyclopedia of the Ancient World. Salem Press, 2002, 868. Also see Patrick Hunt, “Imperium and Genius in the Pantheon of Rome”, Electrum Magazine, May, 2016 (http://www.electrummagazine.com/2016/05/imperium-and-genius-in-the-pantheon-of-rome/).
 Amanda Claridge. Rome: Oxford Archaeological Guides. Oxford University Press, 1998 (2010 printing), 201-7, esp. 206 & 226-33.
 Luisa Carlei, Simonetta de Felicis Orlandi, Paola Ferraris, Maria Cristina Marhei and Gabriele Borghini, eds. Marmi Antichi. Rome: Edizione de Luca, 1997. Note pp. 214-5 (Giallo Numidiana or Giallo antico); pp. 218-9 (Granito Bigio varieties, possibly from Algeria, Egypt or Pyrenees?); p. 264 (Docimian Pavonazetto or Marmor Phrygium); p. 274 (Imperial Porphyry or Porfido Rosso); p. 279 (Lapis Lacedaemonius or Porfido Verde).
 Konstantin Klein. “Wo Josephine sich einst verkohlte” (Karlsthron). Archäologische Kolloquium, Universität Bamberg May 15, 2007. Summarizing the research of archaeologist Dr. Sven Schütte, who established that the original Karlsthron wood seat dates to 800, the same time as Charlemagne’s coronation journey to Rome. Schütte also underscores the similarity of this hued marble to that of the Holy Sepulcher, including the divided column that became the throne stairs. Also see Sven Schütte, “Der Aachener Thron” in M. Kramp (Ed.): Krönungen, Könige in Aachen – Geschichte und Mythos. Verlag Philipp von Zabern, 1999, 213–222.
 Patrick Hunt. “Summus Poeninus on the Great Bernard Pass”, Journal of Roman Archaeology XI (1998) 264 & ff.
 Klein notes: “According to Schütte, it was of fundamental importance for the kings who were crowned on the [Karls]throne to be “connected” with the material.” Also note Herta Lepie and Georg Minkenberg, The Cathedral Treasury of Aachen, Schnell – Steiner, Regensburg, 2013, 2nd ed. 64-5 where the coronation on Charlemagne’s Throne of 30 kings and 12 queens was directly associated with holy relics and their assumed power and sanctity from 936-1541.
N.B. The author thanks a good friend, Rick Winningham, for encouraging his recent revisit to Charlemagne’s Throne in Aachen.