This is in very many respects a pioneering book. It covers the whole Iberian Peninsula over a period of more than five centuries and deals with hundreds of painted and sculpted altarpieces under three broad headings: ‘Form’, ‘Environment’ and ‘Message’. Many of the works are poorly published. An exceptionally valuable contribution of the book is that it publishes, in generally very good photographs, a great quantity of important works of art, which are rarely illustrated systematically. After a brief historiographical introduction the altarpieces are discussed from an art historical stand-point (Form), in terms of their liturgical setting (Environment) and iconography (Message). Whilst this does involve a certain amount of repetition, and the author is prone to frequent summaries this organisation is generally helpful. Kroesen has travelled indefatigably, is enviably at ease in the Spanish and Portuguese literature, and is well-read in current discussions of the altarpiece, although here there are significant omissions. The translation reads mostly smoothly but there are serious and irritating flaws. The translator is unfamiliar with the technical terms generally used in contemporary discussion of the argument. Thus the vertical compartments of these multi-compartmented altar places are misleadingly called ‘lanes’, the dossal has become a dorsal and the Italian altarpiece was called a palla (simple translation would have revealed this last as nonsense). More worryingly it seems that the author as much as his translator believes Franciscans and Dominicans to be monks. The sections on the liturgy are however generally well-informed and up-to-date. Kroesen builds on, and significantly advances, the work of Judith Berg Sobré, Behind the altar table (1989) who dealt only with painted altarpieces. A wider familiarity with Italian examples, particularly in marble would have saved the author from several mis-statements. A more thorough discussion of the carpentry of the wooden altarpieces would have been helpful, although here unawareness of several important recent discussions of wooden altarpiece structure in Italy would have saved him from error. In the discussion of imagery, particularly of the gigantic later altar ensembles at Seville, Toledo and Orense little is said about their visibility to the average viewer – messages to be effective must surely be broadly legible. More might have been said about patronage and the contractual framework of the altarpiece commission. These grumbles should certainly not obscure the multiple merits of Kroesen's book. It brings a great deal of new material into general discussion. There are important treatments of choir-screens and the spatial location and development of the choir in Spanish churches. It contains an unsurpassed photographic documentation. No-one interested in the medieval or Renaissance altarpiece as a European phenomenon can afford to neglect this book.