Painting Mona Lisa. Jeanne Kalogridis

the cavernous Church of Saint Mary of the Flower – in this case a lily. The sanctuary was one of the largest in the world, and was built in the shape of a Latin cross. Atop the juncture of the arms rested the architect Brunelleschi’s greatest achievement: il Duomo. Dazzling in its sheer expanse, the huge dome had no visible means of support. Visible from any part of the city, the orange brick cupola majestically dominated the skyline, and had, like the lily, become a symbol of Florence. It stretched so high that, when he first set eyes upon it, Baroncelli thought it must surely touch the Gates of Heaven.

      Baroncelli dwelt in a far lower realm this particular morning. Though the plan had seemed simple enough to be foolproof, now the painfully bright day had dawned, Baroncelli was overwhelmed with foreboding and regret. The latter emotion had always marked his life: born into one of the city’s wealthiest and most eminent families, he had squandered his fortune and fallen into debt at an advanced age. He had spent his life as a banker, and knew nothing else. His only choices were to move wife and children down to Naples and beg for sponsorship from one of his rich cousins – an option his outspoken spouse, Giovanna, would never have tolerated – or to offer his services to one of the two largest and most prestigious banking families in Florence: the Medici, or the Pazzi.

      He had gone first to the most powerful: the Medici. They had rejected him, a fact he still resented. But their rivals, the Pazzi, welcomed him into their fold; and it was for that reason, that today he stood in the front row of the throng of faithful beside his employer, Francesco de’ Pazzi. With his uncle, the knight Messer Iacopo, Francesco ran his family’s international business concerns. He was a small man, with a sharp nose and chin, and eyes that narrowed beneath dark, disproportionately large brows; beside the tall, dignified Baroncelli, he resembled an ugly dwarf. Baroncelli had eventually come to resent Francesco more than the Medici, for the man was given to fits of temper and had often loosed a nasty tongue on his employee, reminding Baroncelli of his bankruptcy with stinging words.

      In order to provide for his family, Baroncelli was forced to grin while the Pazzi – Messer Iacopo as well as young Francesco – insulted him, and treated him as an inferior when in fact he came from a family with equal, if not more, prestige. So when the matter of the plot presented itself, Baroncelli was presented with a choice: risk his neck by confessing everything to the Medici, or let the Pazzi force him to be their accomplice, and win for himself a position in the new government.

      Now, as he stood asking God for forgiveness, he felt the warm breath of a fellow conspirator upon his right shoulder. The man praying just behind him wore the burlap robes of a penitent.

      Standing to Baroncelli’s left, Francesco fidgeted and glanced right, past his employee. Baroncelli followed his gaze: it rested on Lorenzo de’ Medici, who at twenty-nine years old was the de facto ruler of Florence. Technically, Florence was governed by the Signoria, a council of eight priors and the head of state, the gonfaloniere of justice; these men were chosen from among all the notable Florentine families. Supposedly the process was fair, but curiously, the majority of those chosen were always loyal to Lorenzo, and even the gonfaloniere was his to control.

      Francesco de’ Pazzi was ugly, but Lorenzo was uglier still. Taller than most, and muscular in build, his fine body was marred by one of Florence’s homeliest faces. His nose – long and pointed, ending in a pronounced upward slope that tilted to one side – had a flattened bridge, leaving Lorenzo with a peculiarly nasal voice. His lower jaw jutted out so severely that whenever he entered a room, his chin preceded him by a thumb’s breadth. His disturbing profile was framed by a jaw-length hank of dark brown hair.

      Lorenzo stood awaiting the start of the Mass, flanked on one side by his loyal friend and employee, Francesco Nori, and on the other by the Archbishop of Pisa, Francesco Salviati. Despite his physiognomic failings, he emanated profound dignity and poise. In his dark, slightly protruding eyes shone an uncommon shrewdness. Even surrounded by enemies, Lorenzo seemed at ease. Salviati was a Pazzi relative, and no friend, though he and Lorenzo greeted each other as such; the elder Medici brother had lobbied furiously against Salviati’s appointment as Archbishop of Pisa, asking instead that Pope Sixtus appoint a Medici sympathizer. The Pope had turned a deaf ear to Lorenzo’s request, and then – breaking with a tradition that had existed for generations – he fired the Medici as the Papal bankers to replace them with the Pazzi – a bitter insult to Lorenzo.

      Yet today, Lorenzo had received the Pope’s own nephew, the seventeen-year-old Cardinal Riario of San Giorgio, as an honoured guest. After Mass in the great Duomo, Lorenzo would lead the young Cardinal to a feast at the Medici palace, followed by a tour of the famed Medici collection of art. In the meantime, he stood attentively beside the Riario and Salviati, nodding at their occasional whispered comments.

      Smiling while they sharpen their swords, Baroncelli thought.

      Dressed unostentatiously in a plain tunic of blue-grey silk, Lorenzo was quite unaware of the presence of a pair of black-frocked priests standing two rows behind him. The tutor to the Pazzi household was a youth Baroncelli knew only as Stefano; a somewhat older man, Antonio da Volterra, stood beside him. Baroncelli had caught da Volterra’s gaze as they entered the church and had glanced quickly away; the priest’s eyes were full of the same smouldering rage Baroncelli had seen in the penitent’s. Da Volterra, present at all the secret meetings, had also spoken vehemently against the Medici’s ‘love of all things pagan’, saying that the family had ‘ruined our city’ with its decadent art.

      Like his fellow conspirators, Baroncelli knew that neither feast nor tour would ever take place. Events soon to occur would change the political face of Florence forever.

      Behind him, the hooded penitent shifted his weight, then let go a sigh which held sounds only Baroncelli could interpret. His words were muffled by the cowl that had been drawn forward to obscure his features. Baroncelli had advised against permitting the man to assist in the assassination – why should he be trusted? The fewer involved, the better … but Francesco, as always, had overridden him.

      Where is Giuliano? the penitent whispered.

      Giuliano de’ Medici, the younger brother, was as fair of face as Lorenzo was ugly. The darling of Florence, he was called – so handsome, it was said, that men and women alike sighed in his wake. It would not do to have only one brother present in the great cathedral. Both were required, or the entire operation would have to be called off.

      Baroncelli looked over his shoulder to glance at the shadowed face of his hooded accomplice and said nothing. He did not like the penitent; the man had injected an undertone of self-righteous religious fervour into the proceedings, one so infectious that even the worldly Francesco had begun to believe that they were doing God’s work today.

      Baroncelli knew that God had nothing to do with this; this was an act born of jealousy and ambition.

      On his other side, Francesco de’ Pazzi hissed. ‘What is it? What did he say?’

      Baroncelli leaned down to whisper in his diminutive employer’s ear. ‘Where is Giuliano?’

      He watched the weasel-faced Francesco struggle to suppress his stricken expression. Baroncelli shared his distress. Mass would commence soon now that Lorenzo and his guest, the Cardinal, were in place; unless Giuliano arrived shortly, the entire plot would evaporate into disaster. It was unthinkable, there was too much danger, too much was at stake; too many souls were involved in the plot, leaving too many tongues free to wag. Even now, Messer Iacopo waited alongside a small army of fifty Perugian mercenaries for the signal from the church bell. When it tolled, he would seize control of the government palace and rally the people against Lorenzo.

      The penitent pushed forwards until he stood alongside Baroncelli; he then raised his face to stare upwards at the dizzyingly high cupola overhead, rising directly above the great altar. The man’s burlap hood slipped back slightly, revealing his profile. For an instant, his lips parted, and brow and mouth contorted in a look of such hatred, such revulsion, that Baroncelli recoiled from him.

      Slowly, the bitterness in the penitent’s eyes eased and the muscles in his face relaxed to the point that his expression resolved into one of beatific ecstasy, as if he could see God Himself and not the great ceiling’s