It's 1459 and newish Pope, Pius II is looking for a venue to launch his big idea: Crusade against the Turks. He'd like to have it in Venetian Udine but La Serenissima - five years into a peace treaty with the Porte - is not keen to be linked so closely to a flagrant provocation. So Pius has to settle for Mantua, second-tier as far as Renaissance Italian states go. The Marquis of Mantua is an ex-Soldier of Fortune made good, Ludovico Gonzaga, a poor-man's Francesco Sforza, looking to buff his reputation. He'll earn his seventeen-year-old son Francesco a Cardinal's hat in return for hosting.
Mantua, it's fair to say, is a disappointment for Pius in every way. Firstly the place turns out to be a dump: marshy and unhealthy, the wine was poor, the food scarce and nothing could be heard save the croaking of frogs.
Secondly no one turns up; at least for some time and then, when delegations do begin to trickle in late it, is clear that few if any of the important heads of Christendom have deemed it worthy of their presence.
The Venetians send a delegation along three months after the council has begun. Ludovico Foscarini is the patrician who must have drawn the shortest straw. He does his best to mollify an angry pontiff and the Venetian case is quite reasonable - since the danger posed by the Turks is common, so should be the cost - but to Pius it sounds like the dissembling of merchants who are getting rich from trading with the enemy.
To make matters worse, the Venetian with the most prestige at Mantua is Cardinal Carmelengo, Patriarch of Aquileia and war hero against the Turks at Lesbos, Ludovico Trevisan. But rather than backing his Vatican boss and cajoling his fellow Venetians to be more hawkish, Trevisan is publicly against crusade.
Venice tries again to mend fences and pledges a significant fleet and arms to a coalition task force, stipulating only that they should be in command. Perhaps this sounds too much like 1204 and another Crusade that was hijacked by Venice for ulterior means. Milan and others won't accept it.
While all this is going on, down the road in Verona, Andrea Mantegna is painting the Agony in the Garden. His Jerusalem is clearly Constantinople - you can see the hippodrome, Theodosian walls and even Justinian's equestrian statue. The pinnacle of every tower has the Turkish crescent moon.
The sleeping disciples might be read as the Princes of Christendom.
Meanwhile poor Pius sits agonising in the gardens of Mantua for half a year, pestered by flies and French diplomats who want to talk about Naples, and sees his dream of emulating Pope Urban die with the autumn leaves.
Mantua was a classic example of why Crusades rarely got off the ground. Despite the clear and present danger represented by Mehmed II, despite the shock of Constantinople's fall, despite a relative lull in European conflicts, despite all the efforts of the Pope there was just too much distrust of one another among Christian rulers. For most the threat of the Turks was too distant and the benefits of a recovered Constantinople (or even Jerusalem) too intangible while the costs were certain and heavy.
Pius got his crusade of sorts in the end but it was a fragmented coalition made up of those with little choice but to fight - Venice, Hungary, Albania. The Burgundians promised much and might even have delivered but with no suitable figurehead to lead the ragtag army, Pius dutifully undertook to shoulder the cross himself and unsurprisingly given his age and health, died at Ancona while the fleet assembled. With Pius died much of the religious dynamism to confront the Turks. Venice and Hungary continued to struggle with Mehmed but that was a defensive struggle for control of trade routes and territory, stripped of all ideology. There were no plans for a reconquista of the Bosporus. Without the harangue of a pontiff it was easier for Western princes to look away from the dreadful, costly struggle that threatened to bleed Venice white and pretend it had nothing to do with them.
Despite their name, the Tarocchi di Mantegna were not produced by him but at least 1 historian claims they were devised at the Council of Mantua. Not tarot cards but instructional humanist engravings seeking to reconcile Neoplatonism & Hermeticism with philosophical Christianity.
Placed edge to edge they form a symbolic ladder leading from Heaven to Earth or seen from bottom to top, it teaches that man may gradually raise himself in the spiritual order and that science and virtue bring him closer to God.
But then I am reminded also that at Mantua was Cardinal Juan de Torquemada, uncle of the infamous Tomas and we are less than 20 years from the establishment of the Inquisition.