No sweet chestnut finds were shown to have been grown in Roman Britain. One of the sweet chestnut peelings excavated at the Roman site of Great Holts Farm in Boreham, Essex. (IMAGE: Historic England)The project team is now trying to pinpoint the timing of the sweet chestnut tree’s arrival to Britain using dendrochronological techniques, cross-dating sweet chestnut tree-ring series with established oak tree chronologies. Using this method, some of Britain’s sweet chestnut trees have been precisely dated for the first time, with the oldest dating to AD 1640. The researchers are also working on using DNA analysis of sweet chestnut trees across Britain and Ireland to identify their European ancestral source in order to determine exactly when and from where the trees first came to Britain.