This volume is by Seth Lerer, the famed lecturer of "The History of the English Language" for the Teaching Company. It's not a comprehensive history but a series of essays on turning points in the language.
In one chapter Lerer notes that, during the Great Vowel Shift, words that included -ea- went from an "ay" pronunciation to an "ee" pronunciation. So meat was originally pronounced like "mate" and shifted to our present-day "meet" sound.
But, Lerer notes, there are precisely five words in English that didn't make the shift. Four are nouns, and one is a proper name. If you want to test yourself, make your guesses and scroll down to the small type below.
(Answers: great, break, steak, yea, and Reagan all retained the long "ay" sound.)