- Ingrid D. Rowland –
Giovanni Nanni did well in the Order of Preachers; by 1464 he had moved to the
convent of Santa Maria Novella in Florence and was engaged in the course work that
would lead to a degree as doctor of theology. By 1469 he was back in Viterbo as a magister,
a professor; two years later he had been transferred to the Genoese convent of Santa Maria
in Castello, where he would stay for 18 years.
True to his vocation, Magister Giovanni believed fervently in the righteousness of
the Church and its cause, and became a fi ery preacher on behalf of crusading against the
infi del. Like many Dominicans of his epoch, he also thundered against the high interest
rates charged by Jewish moneylenders, in a printed pamphlet.^3 He decried the feuds
between noble families that had turned so many Italian cities, including Genoa and
Viterbo, into bloody battlegrounds. In Genoa, in 1478, he also made a dramatic political
speech; brandishing an intercepted letter from the Milanese warlord Francesco Sforza,
Magister Giovanni induced the citizens of Genoa to resist the Milanese – which they
did successfully – by the sheer force of his courage and eloquence.^4 In Genoa, too, he was
sought after as an astrologer, and published a visionary prediction “About the Future
Triumphs of the Christians” (De futuris christianorum triumphis), printed in 1484.^5
All told, the friar from Viterbo seemed destined for a great career, until, in November
of 1488, he fell sick with what he would describe as an ear infection that spread across
the side of his head and turned into an abscess of the brain – an extremely dangerous
condition even in our age of antibiotics and still more potentially lethal in the fi fteenth
century. Desperate, he called upon the Immaculate Virgin Mary for help, invoking her
by a title no Dominican would ever normally use. Fifteenth-century Christians had been
arguing strenuously with one another about whether Mary had been born, like her son
Jesus, without sin, or as a normal human baby. The Dominicans were convinced that
Mary had been born fully human and fallible, but the Franciscans and Augustinians
insisted that she had been as pure as Christ from the very beginning, spotless – that is,
“immaculate” – from the moment of her own conception by her parents Joachim and
Anna. Magister Giovanni’s prayer to the Virgin Immaculate tested the question by asking
for a miracle, and the miracle took place. His terrible infection burst through his eardrum,
Magister Giovanni began to recover, and on Christmas Eve of 1488 he made an offi cial act
of devotion, dedicating himself, body and soul, to the Immaculate Virgin Mary.^6
Not everyone saw this sudden cure as a blessing, least of all Magister Giovanni’s fellow
Dominicans, for whom his combination of proven oratorical skills and new theological
insight promised to make him a most inconvenient presence, a Dominican who favored
the opposing side in a theological debate the order knew it was beginning to lose. His
superiors interrogated him about the Immaculate Conception and he proved adamant
in his newfound convictions, so they sent him into early retirement, returning him in
spring of 1489 to Viterbo and his home convent of Santa Maria in Gradi. The transfer was
an exile, but the city council of Viterbo made it a constructive exile, engaging Magister
Giovanni to deliver a series of lectures on local history. Stubborn to the core, he continued
to sign documents as “Iohannes Nannius, professor of theology.”^7
Although he claimed to know almost nothing about his city when he began, Magister
Giovanni set to work on his new assignment as city historian with characteristic energy,
and a remarkably wide-ranging idea of what might count as useful research.^8 Although
his own training had been strictly traditional, running to the memorization of a
demanding technical vocabulary, elaborate syllogisms, and long strings of questions and
answers about Christian theology, metaphysics, and natural philosophy, the middle-aged