Beehive querns are a characteristic later pre-Roman Iron Age type, although their chronology has yet to be refined. They were the first characteristic quern shape to be introduced into Britain. The horizon of their introduction is likely to be late in the 4th century BC and they remained in use until replaced by Roman rotary querns, perhaps from late in the first century AD, a process which may have extended over at least a century, although, again, the chronology has yet to be clarified.
In West Yorkshire querns are important as an indicator of the general distribution of later pre-Roman Iron Age settlement, subject to the usual caveats regarding the presence or absence of fieldworkers and museums, and other variables affecting their discovery and reporting.
Querns are particularly prevalent in the valleys of the rivers Wharfe and Aire, the distribution thinning out on the Pennine uplands and in the lower parts of the Vale of York. This pattern presumably reflects limited populations, but the thinning of the distribution in South Yorkshire may be a function of observation and recording. Within the general distribution pattern it is of particular interest to note the iffering distribution of ‘tall’ querns with sides of greater than 70 degrees to base and 'hemispherical' querns with sides of less than 60 degrees to base. While hemispherical querns are particularly found in North Yorkshire and the Tees valley, ‘tall’ querns are a feature of West Yorkshire, suggesting a cultural distinction which may also be reflected in the ritual and burial traditions noted above.
How long it took flat rotary querns to supplant beehive querns remains unclear, but it is likely that the use of beehive querns did not extend into the 3rd century AD.