Eating eyren in Kent

William Caxton, the first person to print a book in English, noted the sort of misunderstandings that were common in his day in the preface to Eneydos in 1490 in which he related the story of a group of London sailors heading down the 'tamyse' for Holland who found themselves becalmed in Kent. Seeking food, one of them approached a farmer’s wife and “axed for mete and specyally he axyd after eggys” but was met with blank looks by the wife who answered that she “coude speke no frenshe.” The sailors had traveled barely fifty miles and yet their language was scarcely recognizable to another speaker of English. In Kent, eggs were eyren and would remain so for at least another fifty years.

From Bill Bryson's 'Mother Tongue: The English Language'.