Nicholas Ostler's "Ad Infinitum: A biography of Latin" is an engaging work of non-specialist history. Faced with the challenge of chronicling a history of around 2800 years of a language, Ostler succeeds remarkably well at conveying both a sense of the whole, and the delights of the particular.
As to be expected, Ostler spends a considerable early portion examining the origins of the Latin language, and the twin destinies of Rome and its characteristic speech. Beyond the details of Roman history, Ostler has some insights into how Latin came to be the language of its empire, in contrast with other ancient regimes. He also has a detailed (in particulars, but again less than comprehensive - a prudent technique for this kind of volume) examination of the entwined cultures and languages of Greece and Rome, and how Latin developed its literature in large degree from Greek influences.
For most classicists, though, and Latinists more broadly, the real eye-openers come when Ostler begins to relate the history of post-Imperial Latin. The waves of tribal migration and invasion, with their various cultural mash-ups, Latin adoptions; the rise, 'triumph', and spread of Western Christianity, and the loss of a Greek heritage, all mark a massive shift in Latin's position, one that isn't immediately obvious.
The break-down of the Imperium, but the emergence of a sense of Romania in Europe, the emergence of vernaculars, the intricacies of scholastic needs (pushing Latin to develop linguistically in a unique way), and then the purism of the Humanists.
Perhaps most intriguing was Ostler's account of Latin in the Spanish Americas, accounts of priests teaching Latin, learning local languages, and writing epics in the language of the Old World.
Ostler's style is readable, his knowledge far-ranging, and his anecdotes amusing. I found at least 3 or 4 things I'd love to look into a little more, and certainly some food for thought in his broader theorisation. Again, in a populist history of this style, endnotes were probably the right choice, even though I find them frustrating. Ostler did supplement them with footnotes for comments (rather than references).
Ad Infinitum: A Biography of Latin