An archaeomagnetic study has been carried out of an area of burnt clay and stone which comprised a hearth in a medieval peasant dwelling at Thurvaston in Derbyshire (Context 0045). Directions of archaeomagnetism in the feature were found to be rather scattered but nevertheless provide good evidence that the material had been heated in the ancient geomagnetic field. Comparison of the mean archaeomagnetic vector in the hearth with the UK Master Curve indicates that the last firing took place either in the period 1100 to 1210 AD or in the period 1450 to 1530 AD. It should be noted that these estimates are of low reliability owing to the poor remanence stability and grouping of the archaeomagnetic vectors.