The Portiuncula indulgence, an important event in Franciscan hagiography, featured prominently in the reports given in the Legenda de vita et miraculis Beatae Margaritae de Cortona. Il libro della beata Angela da Fologno left accounts of her pilgrimages to the Portiuncula in 1291, shortly after she was admitted to the Third Order of St Francis in her native Foligno, and again in 1300. Another celebrated pilgrim was Margery Kempe, the Norfolk mystic, who visited Assisi for the celebration of the Portiuncula in 1414 and met an English friar there. The indulgence was of particular importance for the friars of Umbria and it quickly found its way into the order's missals and liturgical calendars on 1 August. The eighth centenary of the granting of this indulgence was celebrated in 2016 in two ways. First, there was a conference held at Santa Maria degli Angeli, outside Assisi, in July of that year. The acta of the conference, consisting of eleven papers, were published the following year. Secondly, another collection of papers was published in Il Perdono di Assisi; many of those who had contributed papers to the conference appear in the second volumes, which in some respects assumes the form of a catalogue. It contains ten studies on aspects of the indulgence of the Portiuncula from various authors and it is richly endowed with illustrations of various churches, beginning with the Portiuncula, and of medieval manuscripts and incunabula.

Papers for the conference Il Perdono di Assisi e le indulgenze plenarie were contributed by an impressive team of scholars: Maria Pia Alberzoni, Agostino Paravicini, Antonio Placanica, Roberto Paciocco, Fortunato Iozzelli, Stefano Brufani, Paola Monacchia, Maria Grazia del Fuoco, Étienne Doublier, Daniele Solvi and Elvio Lunghi. Among the contributors are some of the leading scholars in the cosmos of Franciscan and Umbrian history and they are exemplified by Iozzelli's paper, ‘Pietro di Giovanni Olivi e l'indulgenza della Porziuncola’, which explores the life and teaching of the Provencąl friar, who studied for some nine years in Paris on the lectorate programme and then lectured for about twenty years at Montpellier, Florence and Narbonne, and particularly his contribution to the debate about the Porticunula indulgence (‘an sit conveniens credere ingulgentiam omnium peccatorum esse data in ecclesia sancte Marie de Angelis in quo procreatus est ordo Fratrum Minorum?’). A date of 1279 had been assigned to his quaestio, which survives in three manuscripts; at this period Olivi was in Rome, where he was consulted by Nicholas iii on the formulation of Exiit qui seminat. It is conceivable that the friar visited Assisi for this feast in this period and learned something about the local Church and its attitude towards the pilgrimage to Assisi for the feast of the Portiuncula. Iozzelli prefers a date between 1279 and 1282. The theological question is introduced and Olivi's arguments against and for the feast are examined. Iozzelli also invokes the testimony of Benedict of Arezzo and Pietro Zalfani. The former cites Masseo Marigniani who accompanied St Francis to Perugia, when he sought the indulgence from Honorius iii and the latter heard St Francis preaching at the Portiuncula in the presence of seven bishops (p. 130 nn. 40–1). Olivi's initial information on the Portiuncula was derived from the hagiographical tradition, especially the Legenda major composed by Bonaventure of Bagnoregio. One of the figures quoted by Olivi was Brother Giles of Assisi in Pierre Péano's edition (p. 71). Some local knowledge of the Church of Umbria, perhaps gleaned from the friars, enabled Olivi to affirm that priests were reluctant to impose attendance at the Portiuncula indulgence in August, because penitents were unlikely to satisfy the conditions of absolution (‘presbyteri gravibus peccatoribus vix tantam penitenciam imponunt quantum est ire ad locum prefatum in tali tempore scilicet mensis augusti, quia raro inventiunt eos dispositos ad condignas penitencias perficiendas’ [Péano's edition, p. 75]). The spiritual benefits of pilgrimage are underlined by Olivi: ‘si gularis devocio ad sanctos et ad sancta loca et ad statum Christi ibidem inchoatum et singularis fideas potestatis ecclesiastice’ (Péano's edition, p. 124). Iozzelli observes that Olivi strikes an apologetic tone – ‘il tono assunto … è fortemente apologetico’. The order's tradition regarding the Portiuncula was summarised by Olivi, who points to the ancient tradition regarding that church and period in which Francis repaired churches by his own hand, including the one dedicated to the Mother of God, and accentuates the divine mandate to restore the ruined church (Péano's edition, p. 67).

Il Perdono di Assisi: storia, agiografia, erudizione contains contrubutors by Andrea Cantile, Luigi Pellegrini, Stefano Brufani (two contributions), Fortunato Iozzelli with Marco Bartelli and Massimo Vedova, Maria Grazia del Fuoco, Paola Monacchia, Daniele Solvi, Luciano Bertazzo and Luigi Marioli. It is richly illustrated with sketches, maps and photographs. Stefano Brufani's ‘Il Liber di Francesco di Bartolo d'Assisi e l’inventio dell’ indulgenza della Portziuncula’, discusses the volume which was written prior to the announcement of the indulgence by Corrado, the bishop of Assisi. The friar attested that he had searched the documentation for this feast in the legends associated with the saint and his followers. The article is followed by an appendix dealing with five documents associated with the feast and its history and ten illustrative figures in the form of photographs or plates. For example, plate 3 records the miracles associated with the Portiuncula. These two volumes constitute a welcome addition to the world of St Francis of Assisi and the evolution of local feasts.