Holy smoke in medieval funerary rites: chemical fingerprints of frankincense in southern Belgian incense burners

PLoS One. 2014 Nov 12;9(11):e113142. doi: 10.1371/journal.pone.0113142. eCollection 2014.


Frankincense, the oleogum resin from Boswellia sp., has been an early luxury good in both Western and Eastern societies and is particularly used in Christian funerary and liturgical rites. The scant grave goods in late medieval burials comprise laterally perforated pottery vessels which are usually filled with charcoal. They occur in most regions of western Europe and are interpreted as incense burners but have never been investigated with advanced analytical techniques. We herein present chemical and anthracological results on perforated funerary pots from 4 Wallonian sites dating to the 12-14th century AD. Chromatographic and mass spectrometric analysis of lipid extracts of the ancient residues and comparison with extracts from four Boswellia species clearly evidence the presence of degraded frankincense in the former, based on characteristic triterpenoids, viz. boswellic and tirucallic acids, and their myriad dehydrated and oxygenated derivatives. Cembrane-type diterpenoids indicate B. sacra (southern Arabia) and B. serrata (India) as possible botanical origins. Furthermore, traces of juniper and possibly pine tar demonstrate that small amounts of locally available fragrances were mixed with frankincense, most likely to reduce its cost. Additionally, markers of ruminant fats in one sample from a domestic context indicate that this vessel was used for food preparation. Anthracological analysis demonstrates that the charcoal was used as fuel only and that no fragrant wood species were burned. The chars derived from local woody plants and were most likely recovered from domestic fires. Furthermore, vessel recycling is indicated by both contextual and biomarker evidence. The results shed a new light on funerary practices in the Middle Ages and at the same time reveal useful insights into the chemistry of burned frankincense. The discovery of novel biomarkers, namely Δ2-boswellic acids and a series of polyunsaturated and aromatic hydrocarbons, demonstrates the high potential for organic chemical analyses of incense residues.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Belgium
  • Boswellia / chemistry
  • Charcoal / chemistry
  • Frankincense / chemistry*
  • Funeral Rites
  • History, Medieval
  • Plant Extracts / chemistry
  • Resins, Plant / chemistry*
  • Smoke / analysis*
  • Triterpenes / chemistry


  • Plant Extracts
  • Resins, Plant
  • Smoke
  • Triterpenes
  • Charcoal
  • boswellic acid
  • Frankincense

Grants and funding

This research was supported by the Belgian Programme on Interuniversity Poles of Attraction (IAP 7/09, iap-cores.be), the special research fund of the KU Leuven (Centre for Archaeological Sciences, ees.kuleuven.be/cas) and the Research Foundation - Flanders (G.0486.12, www.fwo.be). The Research Foundation - Flanders is acknowledged for enabling the acquisition of a new GC-MS instrument. The other funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.