Chapter 6 deals with the two-fold development of OE ō in ME: in Northern ME, it was fronted to [ø:] and then raised to [ü:]/[y:] in a process known as Northern Fronting (NF); in Southern ME, it remained and was raised to [u:] in the GVS. The extracted ME spellings serve to establish the southern limit of NF, and imply that NF started sometime in the thirteenth century, and may not have been complete by 1450. The phonetic nature of NF is subjected to some debate and recent findings regarding its nature and spread are discussed. The Southern raising to [o:] must have started around the mid-thirteenth century, to judge by the ME spellings analysed, thus antedating the GVS by some 150 years. Hence, NF and the GVS were going on at about the same time (though in separate parts of the country) and there is no good reason to exclude NF from any ‘Great Vowel Shift’.