The Parliament of Australia holds a 1297 inspeximus issue of Magna Carta which is displayed in Members Hall at Parliament House, Canberra. The Magna Carta comprises a single page of text on parchment to which is attached the small seal of absence of King Edward I of England by red and green braided silk cords. As part of recent conservation efforts, an investigation of these silk cords was undertaken with a view towards taxonomic identification of the plant species used to dye the cords.
Despite being dyed over 700 years ago, molecular markers and dye compounds were extracted from the cords via aqueous and organic extractions prior to analysis by UPLC and LC-MS-MS. These techniques were utilised the identification of historical dyes against reference materials which were known to be used in the 13 century. These include weld, calendula, golden marguerite (chamomile), and tansy as yellow dyes, madder as a red dye, and woad and indigo as blue dyes.
The small amount of material from the Magna Carta silk cords along with the age of the material made analysis particularly challenging. Nevertheless, sufficient material was extracted for specific plant species to be identified as likely sources of the dyes. These were also verified against known plant extracts, and authentic standard compounds where possible. Identification of plant biomarkers not only aids in conservation efforts but also holds significant potential for the authentication of historical documents and artifacts, as well as evidence for detecting fraud and forgeries. Here we have present the first molecular characterisation of historical plant-derived dyes and related compounds in Australia’s Magna Carta.