The phenomenon of Definite Article Reduction (DAR) is the realization of the definite article in northern British English dialects in a range of vowel-less forms, usually written t' in literature. The origin of DAR is assumed to be the assimilation of the initial fricative of the Middle English definite article þe to produce a te form, a sound change recorded for many dialects of Middle English. This article examines the validity of this hypothesis by analysing the distribution of fricative allomorphs in the modern dialects in comparison with the details of the Middle English change. The predicted distribution of fricative forms is not found at most localities, indicating that the development hypothesis is incorrect, but the available data are too scanty to suggest an alternative model.