Aachen penny of Charlemagne
The Aachen penny of Charlemagne, a Carolingian silver coin, was found on 22 February 2008 in the foundations of the Palatine Chapel in Aachen, during archaeological work in the northeastern bay of the hexadecagon. This is the first discovery of coinage from the time of Charlemagne at Aachen.
Description of the coin
The obverse of the coin features a cross in the centre, surrounded by the Latin inscription CARLVS REX FR[ancorum], which means Charles, King of the Fr[anks]; a cross is placed between FR and CARLVS as a separator. On the reverse, the famous monogram of Charlemagne is in the centre, with the v-shaped execution line. In the monetary reform of 792/794 it was determined that a pound would contain twenty shillings or 240 pennies. The introduction of the new monetary system with broadly unified coinage types (novi denarii) in the Frankish realm was decreed at the Council of Frankfurt in 794. On this coinage type, the relevant mint is named on the reverse inscription - in the case of the Aachen penny found in 2008, the inscription is METVLLO. The silver penny was, therefore, minted in the period after 794 in the city of Melle, in Poitou-Charentes (modern-day France).
The coin was probably deposited during the construction of the Palatine chapel, before the floor was completed. Ulrike Hecker said, "The coin was found in the backfill from the excavation of the grave of 1910, which was made in an area of intact flooring. This origin leads to the conclusion that the Carolingian floor was first laid after 794."  The penny, then, along with dendrochronological finds and the literary records of Einhard and Sigebert of Gembloux, is of great significance for dating the beginning of construction of the Carolingian Palatine Chapel, which according to this latest discovery can only be dated "soon after 795." 
- Archive of the building manager of Aachen Cathedral: Sanierung der Mosaiken, Marmorverkleidung und Fußböden im Zentralbau. 2 April 2008, accessed on 5 April 2013 (German).
- Aachen Archaeology Portal: Der Denar Karls[permanent dead link], accessed 5 April 2013 (German).
- Universität Würzburg History Department: Münzreform Karls des Großen, accessed 5 April 2013 (German).
- ame/dpa: Geheimnisvoller Münzfund. In: Focus Online. accessed 5 April 2013 (German).
- Helmut Maintz, "Dendrochronologische Datierung Holzringanker Oktogonkuppel und Fundamentholz Oktogonpfeiler Nr. 7," In Karlsverein / Dombauverein (ed.), Dombaumeistertagung in Aachen 2009, Schriftenreihe des Karlsvereins / Dombauvereins, issue 13, Thouet, Aachen 2011, p.98 (German).
- Andreas Schaub, "Neue archäologische Untersuchungen am Aachener Dom." In Karlsverein / Dombauverein (ed.), Dombaumeistertagung in Aachen 2009, Schriftenreihe des Karlsvereins / Dombauvereins, Issue 13, Thouet, Aachen 2011, p.106f. (German).
- Ulrike Hecker, "Der Tempel Salomos in Aachen – Datierung und geometrischer Entwurf der karolingischen Pfalzkapelle". In Landschaftsverband Rheinland (ed.), Die karolingische Pfalzkapelle in Aachen – Material, Bautechnik, Restaurierung. Wernersche Verlagsgesellschaft, Worms 2012, ISBN 978-3-88462-325-1, p. 59 (Quote translated from German).
- 795…Extruxit etiam Aquisgrani basilicam plurimae pulchritudinis, ad cuius structuram a Roma et Ravenna columnas et marmora devehi fecit (In 795... he also built a basilica of great beauty at Aachen, for the construction of which he had columns and marble brought from Rome and Ravenna) from Sigeberti Gemblacensis chronica cum continuationibus. in Georg Heinrich Pertz et al. (ed.), Scriptores (in Folio) 6: Chronica et annales aevi Salici. Hannover 1844, p. 268–535 (Monumenta Germaniae Historica)
- Ulrike Hecker, "Der Tempel Salomos in Aachen – Datierung und geometrischer Entwurf der karolingischen Pfalzkapelle". In Landschaftsverband Rheinland (ed.): Die karolingische Pfalzkapelle in Aachen – Material, Bautechnik, Restaurierung. Wernersche Verlagsgesellschaft, Worms 2012, ISBN 978-3-88462-325-1, p. 43.