Malcolm begins with Antonio Bruti’s career. He served Venice by negotiating with (and bribing) Ottoman officials, but also by securing from the Sultan its all-important supplies of cereals from Egypt, the breadbasket of the Levant. He was rewarded with the republic’s highest honour, becoming a cavaliere (knight) of the Order of St Mark, and his star seemed to be in the ascendant.

Back in Albania, Giovanni Bruni, his brother-in-law, became Archbishop of Bar and Primate of Serbia, an office that embraced populations in both Venetian and Ottoman territory. Archbishop Bruni became one of the most prominent fathers of the Council of Trent, which gave the impetus to the Counter-Reformation, and enjoyed a reputation as an expert on relations with the Turks in Rome and Venice. But disaster struck when an Ottoman army conquered Albania, including Bar. The Archbishop was captured and enslaved; his province was devastated and Islamised.

His brother Gasparo, meanwhile, had become a leading figure with the Knights of Malta. His linguistic skills and contacts enabled him to function not only in diplomacy but also in espionage: based in Dubrovnik (Ragusa) he gathered intelligence about Ottoman plans to attack Malta. Dubrovnik’s situation midway between the Christian West and the Islamic Orient made it the spy capital of Europe, rather like Berlin (and Bonn) during the Cold War. The Ragusans spied for both sides, of course. In 1568 Gasparo Bruni seems to have played an important role in informing Philip II of Spain about the Granadan revolt of the Moriscos (Muslims forced to convert to Christianity) backed by the Turks.

The complexity of 16th-century diplomacy — shifting rivalries between major and minor powers, tensions between Catholic, Protestant and Orthodox rulers, even collaboration between Christians (especially the French) and Ottomans — meant that the Papacy, the driving force behind the Holy League to defend Christendom, had its work cut out. Malcolm argues that Ottoman aggression was motivated by realpolitik rather than zeal, but he finds the popes of this period ideologically fixated on the reconquest of lands lost to Islam: “Theirs was a project of holy war,” he concludes. “One might almost call it Christian jihad, were it not for one basic difference: their aim was not simply to fight infidels because they were infidels, but to fight them because they ruled over populations of Christians.”

That difference persists to this day, except that most Westerners no longer care enough about Christians under Islam, even when they are persecuted, to make them a casus belli. Not only has the West no appetite for holy — or indeed unholy — wars; it has ceased to have any comprehension of jihadists who do.

When Malcolm comes to Lepanto, his superb narrative is enriched by Gasparo Bruni’s bird’s-eye view of the battle from his vantage point as captain of the Papal flagship. His commander, Marcantonio Colonna, was under strict instructions from Pope Pius V to exclude “beardless boys” to forestall sodomy, but this did not preclude the presence on board of an overpromoted 20-year-old great-nephew of the Pontiff (“an old-fashioned nepotist”). However, the commander-in-chief, Don John of Austria, was only 23. Among the crew of the Venetian admiral’s galley were probably two sons of Antonio Bruti, who were also nephews of Gasparo Bruni.