A new, more reliable technique has been used to determine the ancient intensity of the earth's magnetic field using samples of baked clay from eight sites in the Eastern Mediterranean. The resultant power spectrum reveals a single strong component with a period of 1430 years. The reproducibility of the results obtained with the new method also makes limited archaeomagnetic dating with a precision of between about one and two hundred years between 900 BC and AD 400 possible. ¿ American Geophysical Union 1990