From the perspective of legal history, the evolution of law into a learned discipline in the 12^th century marks a dividing line between the First and the Second Middle Ages. The »rediscovery« of Roman law and its teaching first in Bologna, later all over Europe, and the creation of the »Decretum« by a shadowy figure called Gratian, sparked lively discussions among scholars on a wide array of legal questions. In his »Decretum«, Gratian collected conciliar decisions and papal decretals, among other material. As more people availed themselves to courts of law, the popes increasingly dealt with legal matters, decided legal cases, and answered juridical questions; briefly: they produced decretals. These decretals were collected in numerous local and regional collections, some even reached later collections with a much wider influence, such as the so called »compilationes antiquae« in which the »Compilatio prima« by Bernard of Pavia can be found. Again, some decades later, Raymond of Penyafort, arranged these more recent decretals in his officially published »Liber Extra«, also known as »Decretales Gregorii IX« (1234). This compilation put an end to any private efforts to master the bulk of papal decisions and to align them.

Who was the driving force behind the sky-rocking number of decretals in the second half of the 12^th century? Some scholars presume that the rise in papal power goes hand-in-hand with the number of decretals – a powerful pope displayed his influence in decretals, steering the Church by means of law. As some have argued, a »papal monarchy« evolved. Anne Duggan puts a different interpretation forward. She reassesses the older dichotomy of centre (pope) and periphery (bishops) and proposes a different model, namely a dialogue between popes and bishops rather than a papal monologue. According to her, the popes reacted to the multitude of legal questions which bishops, clerics, monks and nuns, and even the inhabitants of distant places in the north addressed to them.

Their answers were first locally conserved, stored in local or regional collections; they then gained authority and were received by wider spread collections or even the »Liber Extra«, which universities adopted. Or, to put it in other words: decretals needed to stand the local test before they became object of academic discussions. Her model is, biochemically inspired, one of a double helix: the papal curia forms one strand, the bishops the other, and the canonists constitute the backbones linking both helices together (p. 282–283).

Duggan sharped her model in a multitude of articles, some of which are presented in this bulky and opulently presented volume. All articles are quite recent (the oldest dates to 2003) and shed light on different aspects of the evolution of canon law, on »old« and »new« in the 12^th century. The articles elaborate on »Innocent II and the Advances of the Learned Laws« (ch. 1), the contribution of Eugenius III (ch. 2) and Adrian IV (ch. 3) to canon law, and especially the influence that exercised Alexander III (ch. 4–9). The final essays focus on pope Celestine III (ch. 10) and the contribution of episcopal consultations to shaping canon law (ch. 11–14). They are all tied together by a fine introduction by Travis Baker, who edited this volume.

The volume offers a coherent collection of thematically fitting articles that explore Duggan’s main hypothesis from different angles. The new setting of the articles, its appealing layout, the index covering all articles, and a bibliography make this collection of older essays a new book which is more than its older components (and which is, indeed, much than a mere reprint of seminal articles offered by other publishers). The drawback, however, is that the old pagination dropped out and corrections were made silently [p. 9] which hamper the use of this book when older references are at hand. Nonetheless, Duggan’s collection offers a refreshing view on canon law in the 12^th century, on popes, bishops, and canon lawyers.