The first attempts - Soft tissues
In the 1950ies, plant pollen found in the old peat cutting in which Grauballe Man was found indicated that he was put in here around the birth of Christ. Radiocarbon dating of his liver in 1957 suggested a date of c. AD 310. At the time, radiocarbon was a very new dating method, which has been refined a lot since then. By the 70ies, it was realised that humic acid from the decaying plants above Grauballe Man could have contaminated the sample. Therefore, Henrik Tauber of the Copenhagen laboratory removed this contamination before another dating attempt in 1979, this time using a sample of muscle and possible stomach tissue. It returned a considerable older date range of c. 110 BC – 50 AD.
Another date - Hair
In 1996, a hair sample was dated. Unlike bone and soft tissue, hair is not affected much by the acid bog environment, making it an ideal material for dating. The date range returned was 390 BC - 210 BC. This placed Grauballe man in the Early Iron age, the period to which most other Danish bog bodies date.
Final dating attempt - Bone and the bog
A final dating attempt was made during the new investigations in 2002. This time, a sample of bone from Grauballe Man’s pelvis was used. A radiocarbon date range of 150 BC – 30 AD was found. However, the bone sample is likely to have been contaminated with more recent substances during the artificial tanning of the body which was part of its conservation in the 1950s. this would make the sample appear younger. Thus, the date of the hair sample is probably most reliable. This is reflected in the date of some of the plant roots found in Grauballe Man’s gut, which had grown there after he was deposited in the bog. These plant roots were dated to 490-230 BC. The results of the various dating attempts demonstrate that Grauballe Man died around 400-200 BC, and most probably around 390 BC.