Early Medieval Europe; The High Middle Ages; The Later Middle Ages; The Renaissance; The Reformation
Numerous articles, book chapters, and book reviews, and four books:
High way to Heaven. The Augustinian Platform between Reform and Reformation, 1292-1524. Brill Academic Publishers: Leiden (2002), and Creating Augustine. Interpreting Augustine and Augustinianism in the Later Middle Ages. Oxford University Press: Oxford, 2012;
Catechesis in the Later Middle Ages vol. 1: The Exposition of the Lord’s Prayer of Jordan of Quedlinburg, OESA (d. 1380)–Introduction, Text and Translation. Brill Academic Publishers: Leiden, 2015;
Luther and the Reformation of the Later Middle Ages. Cambridge University Press: Cambridge, 2017. Co-editor of and major contributor to The Oxford Guide to the Historical Reception of Augustine, 3 vols. (Oxford, 2013). Work in Progress: Catechesis in the Later Middle Ages vol. 2: The Meditations on the Passion of Christ of Jordan of Quedlinburg, OESA (d. 1380)–Introduction, Text and Translation History, Myth and Ideology I. The Sermons of St. Augustine Collected by Jordan of Quedlinburg, OESA (d. 1380)–Introduction, Text and Translation Roberti de Bardis Collectorii Sermonum Sancti Augustini Registrum.
Medieval, Renaissance, and Reformation Europe, Religious, Intellectual, and Political History of the 14th-16th centuries, the Augustinian tradition and the Augustinian order, late medieval textual culture, textual/literary theory and text editing.
Editoral Board for the series Studies in the History of Christian Traditions, of Brill Academic Publishers