The Impact of the Crusades 105
The next case study in the Decretum, Causa 24, was also important for cru-
sading—particularly for crusades against heretics and political enemies of the
papacy—because it dealt exclusively with writings of the Church fathers about jur-
isdiction over heretics. It detailed another fictional case, this time of a bishop who
had deprived priests of their office and declared them excommunicated, but who
after his death was himself accused of heresy and—with his followers—officially
condemned. In Quaestio 1 gratian asked whether a heretic could deprive others of
office or pronounce them excommunicated, in Quaestio 2 whether someone could
be excommunicated after death, and in Quaestio 3 whether a man’s family should be
excommunicated for his personal sins. Again he drew on traditional authorities to
argue that the Church must defend itself and be defended against heresy.
The emphasis which the Decretum placed on the need to fight to defend the
Church from its enemies was a familiar theme to theologians, and canon lawyers
and popes as early as the eleventh century. Nicholas II (1058–1061) declared that
anyone who tried to seize the prerogatives of the roman Church (‘romanae eccle-
siae privilegium’) conferred by Christ, fell into heresy because his action injured
Christ himself, while peter damian (c.1007–1072/3) declared that anyone who set
aside the idea of papal privilege and failed to show obedience or seek the advice of
the Apostolic See was a heretic.18 Indeed years before Urban II authorized the First
Crusade the canonist Anselm II of Lucca (1036–1086) had compiled a collection of
legal documents endorsing the Church’s right to employ violence against enemies of
the peace, excommunicates, and heretics—a collection on which the Decretum drew
extensively to defend the employment of ecclesiastical officials to punish heretics.
The collections of papal letters—known as decretals—made by canon lawyers in
the twelfth and thirteenth centuries were commonly referred to as Decretales extrav-
agantes—since they ‘wandered outside’ gratian’s Decretum—and they multiplied
rapidly in the last third of the twelfth century.19 Of these, some of the most influential,
each containing five books, were known collectively as the Quinque compilationes
antiquae and—since they became the standard source for papal decretals—were
cited as authoritative texts from the moment of their compilation. The importance
of the Quinque compilationes antiquae was reflected in the sheer number of summae,
glossae, and apparatus (collections of glosses) analysing them which appeared
throughout our period.20
An even more influential factor in the development of canon law was the Liber
extra decretalium, or Liber extra of raymond of peñafort (c.1175–1275), an offi-
cial collection of papal decretals commissioned by gregory IX in 1230. Although
less bulky than the Decretum which it supplemented, it was still over 30,000 words
and its influence on later canon lawyers is evident from the fact that it was the
subject of systematic exposition and study at Bologna and elsewhere—as we see by
many thirteenth-century commentaries on it. raymond was one of many
Bolognese authors to make constant use of the Quinque compilationes antiquae
18 Gratian, d.22. c.1, col. 73.
19 John Clarence Smith, Medieval Law Teachers and Writers, Civilian and Canonists (Ottawa,
1975), p.32.
20 rist, The Papacy and Crusading in Europe, 1198–1245, p.122.