Years (eighteen) in the making, this astonishing and massive accumulation of learning contains about 5000 initialed articles contributed by about four hundred authors from all the relevant academic disciplines, under the general editorship of Oliver Nicholson and teams of area editors and area advisors whose reputation and expertise give a priori authority to the work. The contents cover every aspect of the history of “late antiquity,” which is here defined in time as the half millennium from the mid-third century to the mid-eighth, and in space as Europe, west and central Asia, and Africa north of the Sahara. The end point means oddities like articles on Charles Martel, Pippin III, and the Pirenne Thesis but none on Charlemagne. The starting point includes the emperor Decius (d. 251) but not the emperor Philip the Arab (d. 249). Better would have been c. 200–800 CE, though that might have meant another volume. A concern, given the gestation time, is bibliography. This reviewer can vouch for the inclusivity (geographic, linguistic, ethnic, religious), the value, and currency of articles and bibliography in areas in which he has been working (ecclesiastical historiography, chronicles). Invaluable contributions include a virtual monograph on Persia (sixteen double-column pages, many aspects) and a brace of articles on “Inscriptions” (five double column pages). Not just massive and learned, but fascinating (for example, editor Nicholson's one column entry on “deer”). Appendices include Roman Emperors and Usurpers, Barbarian Kings, Caliphs, and Bishops of the Five Great Patriarchal Sees (in alphabetical order, putting the see of Rome last!). Lucky the scholar who can afford one, and no college, university, or seminary library should be without it. Its breadth of selection and depth of treatment of central topics put it in a class by itself, in a market where questionably useful handbooks go on proliferating per omnia saecula saeculorum.