In Rabbinic and Christian mystical traditions, the Song of Songs occupies a privileged status among the Hebrew Scriptures as the the ‘Holy of Holies’: the most sacred of all sacred books. Generations of readers have drawn spiritual inspiration from its powerfully erotic imagery, construing the sexual union that it describes as a figure of divine intercourse with the nation of Israel, or the Christian Church, or the individual soul. In her study of seventeenth-century English readers, Elizabeth Clarke shows how politically explosive this numinous text could become at a time when the identity of Christ's bride on earth was fiercely contested. Clarke analyses a formidable range of sources, from funeral sermons and commentaries to court masques and emblem books, to explore changing patterns in the Song's interpretation and use, with a particular focus on its shifting symbolic importance as a shibboleth of Reformed Protestantism (characterised throughout, not unproblematically, as ‘Puritanism’). The resulting narrative of seventeenth-century religious politics – from a Reformed consensus to radicalisation to the domestication of dissent – is a familiar one. Clarke sets it out in her epilogue: ‘The discourse of the mystical marriage, which had started the century as characteristic of one influential group in the religious and political mainstream, had by the Restoration become the property of the radical wing of the Nonconformist constituency’, and was then tamed by the privatising interpretations of later dissenting commentators, in the changed environment of the 1670s and '80s (pp. 192–9). This conventional framework takes on fresh texture and colour as Clarke expounds the political reception of the allegory, and her readings are in general characteristically sensitive and astute. The many illuminating passages in the book include her discussions of emblem theory and the nuptial pageantry at the court of Charles i and Henrietta Maria in chapter iii; her interesting suggestion in chapter iv that, following the radically democratic spirituality of the 1640s, Reformed commentaries on the Song were designed less as devotional aids than as didactic guides; and her evocation in chapter v of the resonances which female readers found in the spirituality of the Song. Given the many rewards offered by this book, it is unfortunate that in places its structure is awkward and the framing sparse, so that the reader must persevere in order to tease out its insights. I was not always, moreover, wholly convinced by Clarke's readings, such as the passage in which she presents Donne's Sonnet 10 (‘Batter my heart, three person'd God’), as ‘wittily outrageous’, satirising Calvinist soteriology through the portrayal of a divine rape. I also felt that the narrative of depoliticisation in Reformed readings of the Song was perhaps overdrawn: juxtaposing Matthew Henry's commentary with the Ranter Joseph Salmon's radical prophetic writings does not necessarily provide a revealing comparison. None the less, this is a book of immense value for literary and religious historians alike, subtle in analysis and rigorous in research.