In the last year of his life, while worn down by illness, Wolfgang Amadeus Mozart composed two operas and a Requiem Mass. One opera was an esoteric comedy, Die Zauberflöte (The Magic Flute), and the other was a serious piece set in ancient Rome, La Clemenza di Tito (The Clemency of Titus). Mozart (1756-1791) has become the most beloved of classical composers, probably best known in the version of him in Peter Shaffer’s play from 1979 and film from 1984, Amadeus.

As with any great artist, some of Mozart’s works have become recurring features of popular culture, and others have remained obscure and nearly forgotten. For example, Mozart’s Eine Kleine Nachtmusik is easily recognizable from film scores and commercial advertisements, whereas La Clemenza di Tito disappeared from the repertoire for more than a century. That opera’s tale of the first-century Roman emperor Titus bestowing clemency upon conspirators against him became overshadowed by Mozart’s other operas, especially Die Zauberflöte and Le nozze di Figaro. As Paul Johnson wrote in his life of Mozart (2013), “I have never heard anyone call Tito a great opera,” and yet “no musician rates it less than good.”

Of course Tito (to use the standard shorthand) is good, being by Mozart, but its obscurity could come from its formality. Mozart composed Tito for the coronation in Prague of the Holy Roman Emperor, Leopold II, as King of Bohemia, and its recitatives set to harpsichord give it a stateliness befitting Baroque chambers and royals bedecked in their ceremonial finery. Its vigorous overture has a gilded brightness heralding that something majestic awaits, and Titus makes his grand entrance to one of Mozart’s most stirring marches.

Aside from its setting in classical antiquity, there is an old-fashioned quality to Tito. That is, Mozart was writing new music for an old opera: Tito dated back to 1734, when Antonio Caldara wrote the music for a libretto by Pietro Metastasio. Their opera honored Charles VI, Holy Roman Emperor and grandfather of Leopold II.

Those Holy Roman Emperors give the context for the plot of Tito. As Johnson noted, eighteenth-century Europe was “the Age of the Enlightened Despot,” and of one aristocratic Austrian archbishop of the time he said, “He was all for reform, provided it was imposed from above.” Thus, presenting at a Christian emperor’s coronation an opera about the clemency of a pagan Roman emperor was using history to convey a political message.

However, today anyone thinking about the emperor Titus most likely thinks not about his clemency but about his ruthlessness. Most of what we know about Titus comes from a biography of him written by Gaius Suetonius Tranquillus, known in English simply as Suetonius. Among other positions of trust, Suetonius served as director of the imperial library, and he had access to the imperial archives.

His Lives of the Twelve Caesars, written around 120, tells us about Titus, a son of a Roman general, the future emperor Vespasian. Suetonius records the military career of Titus and notes he was short and stocky, was bilingual in Latin and Greek, and was adept at playing the harp. And yet, before he became emperor, people hated and feared him.

Still standing in Rome is the Arch of Titus, and it commemorates Titus crushing a revolt in Judaea. Titus had served in the Roman army in Britain and Germany before commanding legions in Judaea. There, as part of his campaign against rebellious Jews, he destroyed the Galilean towns of Gamala and Tarichea so comprehensively that not a trace remains, even on a map. Titus then captured Jerusalem, demolished the Temple, and carted off all its treasure, notably its gold and silver and bronze liturgical items. From that loot, Titus funded construction of an amphitheatre in Rome, named for his family and known by its nickname, the Colosseum. Next door he built vast public baths.

While his father was emperor, Titus commanded the Praetorian Guard, part imperial security detail and part secret police. As commandant he used informers to ferret out conspiracies against his father, and he discovered that two senators were planning to assassinate Vespasian. Titus invited one of them to dinner, and as the man left, Titus had him stabbed to death. The other conspirator, denounced by the Senate, slit his own throat.

When Vespasian died, Titus became emperor, and he chose to become magnanimous. As emperor he displayed his common touch by bantering with the crowds in the Colosseum and by sluicing himself alongside the guys at the baths. Thinking he was showing that he had turned away from his brutal police state tactics, Titus had his old informers publicly flogged. He then marched them to the Colosseum, where some were auctioned into slavery and others were exiled to desolate islands.

What Suetonius said next inspired Pietro Metastasio. Two patricians were convicted of conspiring to kill Titus and take over governance of the empire. Titus pardoned them, invited them to dinner, and next day had them as his guests at the Colosseum. As was customary, the swords that the gladiators were to use were brought to the emperor for inspection, but Titus deferred to his two special guests, asking them to inspect the weapons. Then, as a final way of proving there were no hard feelings, Titus consulted the men’s horoscopes to see into their long futures.

Four years before Mozart wrote Tito, some citizens in the new United States of America feared that the President delineated in the proposed new Constitution would become a despot, and probably not an enlightened one. Mozart’s great contemporary, Alexander Hamilton (1755-1804), addressed one of those fears in Federalist 74.

There Hamilton wrote about the proposed President’s pardon power, something critics of the new Constitution claimed ought to be left to Congress. Hamilton noted that “the criminal code of every country partakes so much of necessary severity” that without the power to pardon, “justice would wear a countenance too sanguinary and cruel.” Hamilton believed that the President, rather than Congress, could best be entrusted with the power to pardon. To Hamilton it was clear that “a single man of prudence and good sense is better fitted, in delicate conjunctures, to balance the motives which may plead for and against the remission of the punishment.” It was an ideal shared by Metastasio and Mozart and that went back at least to the days of Titus.