Oh I do swear by Vox Latina, a thoroughly invaluable slim volume. The one problem I have is the apparent preservation of H in French: after all, virtually all H-initial borrowings from Norman French have a pronounced H in Modern English. (Very few exceptions: 'honour', 'heir', 'hour', and dialectally 'herb'.) The simplest explanation for this is that Latin H stayed pronounced in Gaul until past the Conquest, and then disappeared in France but not in England. However, all the other evidence suggests that H disappeared very early, even as Vox Latina says, within the Classical period.

Now a handful of spelling H's could be turned into pronounced ones by scholarly influence, but the whole lot? So Middle English azard, Ector, eritage, ermit, ideous, omage, Omer, orizon, oroscope, ospital, ost, uman, umble, ydraulic, Ymen, ypolydian, and a great many more all of which could have occurred in Chaucer, were spelt with a silent H (in most cases: Ector, eremite, umble survive without), and at some point the spelling influenced the pronunciation and caused the insertion of an H? It sounds so unlikely -- yet I suppose that's what must have happened.