Francesco was convinced that he would be the next Archbishop of Florence, a bishop of high rank yet not of higher sacramental order than deacon or priest. Francesco was filled with rage and hatred when Lorenzo de' Medici stood in his way and swore his revenge against the Medici family. The Templars supported his cause, viewing him as a useful ally with great influence if his quest for power was successful. Made wealthy through his familial connections to Pope Sixtus IV, Francesco also purchased a Tuscan villa in 1475 in anticipation of becoming archbishop of Florence. He spent the next few years having it renovated in the Tuscan style, while plotting with the Pazzi family to invade Florence. 
- "You think a few mercenaries will scare me? Ha!"
- ―Francesco Salviati.[src]
Seeking revenge for the denial of the Archbishop position, the opportunity arose for Francesco with the Pazzi conspirators. While his fellow conspirators attempted the murder of Lorenzo and his brother, Francesco led his men into the city of Florence and began their assault. The fight eventually led to the death of Francesco de' Pazzi by the hands of the Assassin, Ezio Auditore.
While his Templar brothers fled, Francesco Salviati took his leave into the countryside of Italy. Francesco exchanged clothing with a farmer, who was hung, being mistaken for the fugitive. Francesco fled to his villa deep within the Tuscan countryside. He took the simple measures of barricading himself inside of it and surrounding himself with guards out of fear that he would be located and assassinated.
- "He knows you come for him... emerging only in darkness to meet with the others."
- ―Francesco's final words.[src]
With himself barricaded inside his Villa, Francesco's fears were proven correct when the Assassin tracked him down. Ezio Auditore rapidly infiltrated the villa, and made his way past the villa's guards.
Blows were dealt between the two forces and words were exchanged between Ezio and Francesco. However, the former Archbishop was eventually taken down and killed. He revealed that the Templars would meet at night and that they suspected Ezio would find them. Before further information could be extracted, he succumbed to his injuries, and died.
Personality and characteristics
Francesco was an ambitious man, planning his life ahead and yearning for very high-profile positions in society such as being the Archbishop of Florence. While still the Archbishop of Pisa, this wish for greater power was a display of Salviati's greed and possibly a sign of early madness, believing that he could dominate two regions at the same time as Archbishop.
His pride was clearly a weakness of his mind, having led him to joining the Templars. The moment that Francesco felt he had been betrayed by Lorenzo, his hurt pride led him down the path of the secret order and eventually to his death.
Though proud, ambitious and greedy, Francesco was no coward. He led soldiers into Florence upon the moment of the coup and fearlessly fought against Lorenzo's men until one of the members of the conspirators was displayed on the end of a rope, having been defeated and killed by an Assassin. Even as the man fled, he cunningly tricked a farmer into assuming his identity and defended himself against attackers behind the walls of his villa in Tuscany.
Francesco wore a plain white tunic at the time of his death, along with serviceable blue trousers. He was always armed and ready for battle, particularly whilst defending himself from the Assassins in his villa. His hair was just above shoulder-length and deep black, the final ordinary part of his assemblance. His apparel matched his personality, preferring action or simplicity to finery and impracticality.
Behind the scenes
Historically, Archbishop Salviati was the main instigator of the conspiracy, not the Pazzi family. He was supposed to kill Gonfaloniere Petrucci and take hold of the Palazzo della Signoria. However, he was arrested by Petrucci, and hanged by a mob from the window of the Sala dei Duecento, next to Francesco de' Pazzi.
In Assassin's Creed: Renaissance, the Archbishop fled to his estate near San Gimignano and took refuge there in the weeks after the failed Pazzi attack. Ezio, in the company of Mario Auditore's mercenaries, stormed the palace after Ezio disguised himself as a Pazzi soldier. He then encountered him in a courtyard, where Salviati spouted religious nonsense much like his co-conspirator, Antonio Maffei. Instead of fighting, Salviati merely taunted Ezio until he was approached by him. Ezio then held a dagger to his throat, but instead of divulging information, Salviati forced the dagger into his own throat, effectively committing suicide.