16 October, 2023

Archaeobotanical Analysis reflecting Medieval diet

On UN World Food Day 2023 we are sharing some interesting results from inhouse archaeobotanical analyses carried out on one of our urban projects. Food is a necessary component of life, and plant macrofossil analysis can help us to identify the foods of the past and learn about what our ancestors ate. Plant macrofossil analysis involves identifying the seeds found in the soil from archaeological excavations. The seeds are identified to the different plant species and, depending on where they are found within the site, we can learn about what the inhabitants of the site were doing with them. Some seeds are from plants that we eat, some are from plants used for making textiles such as linen, while other plants are simply weeds that were growing in the area. Plants have a very wide variety of uses, and their remains can inform us about many aspects of past activity.

Archaeobotanist Róisín O’Droma examining seeds from Little Mary Street under microscopic magnification.


IAC excavated a site at Little Mary Street in Dublin city, which revealed the remains of a 13th/14th century gatehouse which provided access to the St. Mary’s Abbey precinct. This abbey was the largest medieval complex on the northern side of the river Liffey and was founded in 1139 by French Benedictine monks, though it soon became a Cistercian Abbey. Plant macrofossil analysis was undertaken by our archaeobotonaist Róisín O Droma on soil from cess pits located near the gatehouse. Cess pits were used specifically to dispose of human waste, so they provide direct evidence of what was eaten by the people using them. The seeds identified from the cess pits at Little Mary Street included different wild plants such as apples, blackberries/raspberries (bramble), sloe berries, elderberries, chickweed, and nettles. These plants might have been growing nearby, perhaps in the gardens of the Abbey, and the fruit would have been picked and eaten. Most people had to grow their own fruits and vegetables, forage wild plants and fruit, or buy them at the local markets. Abbeys usually had land for growing their own produce and it was part of the daily life of a monk to labour in the fields.

Identified seeds from Little Mary Street alongside their fresh counterparts, including blackberries, chickweed, elderberries, and sloes.


Other identified seeds show that the monks had access to more exciting fruits than local blackberries and apples. One such fruit that was present in larger numbers were grapes. As this species is not native to Ireland, this plant would have been imported and planted in the Abbey. Perhaps the monks brought them from France when they established the Abbey and planted a small vineyard within its walls. Monks have always been associated with wine production and this site is no different. Fragments of wine bottles and drinking glasses were also found during the excavation. The presence of the grape seeds in the cess pit shows that at least some of the grapes were consumed as unprocessed fruit, and that they weren’t all used for making wine. This would certainly have been quite a treat in 13th/14th Century Dublin!

Róisín O’Droma and Ellie Organ