Heresy and the Making of European Culture: medieval and modern perspectives, (Ashgate, 2013), pp. 383-402.
Evidence suggests that heresy in Lombardy proliferated during the twelfth and thirteenth centuries, a period of upheaval in the structure and form of politics and society, especially in itscapital city. From 1117 Milan operated as a commune, securing independent jurisdiction at thePeace of Constance (1183). From the middle of the thirteenth century the della Torre family dominated Milanese communal office, and by the 1270s the Visconti family had ascended, the start of a lasting signoria . Milan was also embroiled in contemporary struggles between Papacy and empire. Its location on the main trade routes from Venice and the East ensured a strongeconomy, making Milan attractive to migrants, and by the end of the thirteenth century itspopulation had swollen to an unprecedented level – possibly 175,000.
Heresiologists have seen variations between Cathar experiences in northern Italy andother parts of Europe, particularly the Languedoc, especially in organisational structure andsocial status. Given the lively political and social changes taking place there, it seemed fruitfulto analyse this observation by studying Milanese Catharism in the context of theories of urbanism or social mobility. Other case studies of Italian towns and heresy have applied prosopographic and quantitative methods to inquisition evidence. Undertaking similar studiesfor Milan is difficult; in 1788 most Milanese inquisition records were burned in the courtyard of the Dominican convent of Santa Maria delle Grazie by order of the Austrian-Habsburgempress, Maria Theresa.