He was also both father and uncle to Giulio de' Medici, through his mistress and cousin, Fioretta Gorini; though the boy was born a month after Giuliano's death.
While his brother Lorenzo took on the role of a statesman, Giuliano was something of a playboy, becoming known for his jousting tournaments and handsome physique. On April 26, 1478, Giuliano attended High Mass in Florence with his mistress, and his brother Lorenzo. However, before they could enter the Santa Maria del Fiore, they were attacked by the Pazzi conspirators.
Bernardo Baroncelli delivered the first blow, and slashed Guiliano in the chest. As Francesco de' Pazzi advanced on him, Guiliano begged for mercy, but Francesco refused, and stabbed him nineteen times in the chest, killing him.
A month after Giuliano's death, his son Giulio was born. Giulio was considered legitimate due to a loophole in Canon law, allowing marriages to occur privately between two people. This meant that parents could have agreed that they were married without informing anyone. Giulio later became Pope Clement VII.
- After saving Lorenzo de' Medici in "Wolves In Sheep's Clothing", Ezio could loot and pick up Giuliano's dead body.
- Strangely enough, the blood in the left his neck where he is first stabbed by Baroncelli, disappears when Francesco begin to stab him until the 19th time in the chest.
- Historically, aside from the frenzied stabbing by Baroncelli, Giuliano was also stabbed by Francesco in the skull, a detail omitted from the game.