Cristina was born in Florence, Italy and grew up to be one of the most beautiful women the region had to offer. She was adored by many young men, such as Ezio, who saw her one night in 1476 and approached her after the encouragement of his brother Federico.
However, as Cristina was used to be hit on, she simply turned Ezio down. Being kind of a womanizer and unused to be turned down, Ezio followed Cristina to her home, just to witness a nasty scene between her and one of her admirers, Vieri de' Pazzi.
After Vieri got turned down, he begins to harass Cristina, but is interrupted by Ezio. A short fistfight began, but Vieri was inferior and ran away after being shamefully defeated by Ezio. Cristina, impressed by Ezio's chivalry, thanked him and the two eventually started a relationship.
Ezio regularly visited Cristina at her home, and although the guards were aware of his trespassing, they were never able to catch him. But he was once discovered by Cristina's angry father in the morning, who set the guards on him, but Ezio escaped.
After the execution of both Ezio's father and brother, it was Cristina who arranged the burning and proper funeral.
When Ezio had to leave for Monteriggioni, he asked Cristina to come with him. She refused though, as she didn't want to leave her family behind. Accepting her decision, Ezio gave her a pendant to remember him by.
In 1478, Cristina married Manfredo Soderini, but more because of her father's will than her own. Just one day before their wedding, Ezio returned to Florence and visited Cristina, unaware of the direction her life had taken. Cristina told Ezio she didn't expect him to return and reveals her engagement. Even though he is heartbroken, it is Ezio who appeals to Manfredo's conscience, telling him to stop gambling and start being a good husband. Ezio states if not, he would hunt him down and kill him. Ezio then returns to Cristina, both share a kiss, and then part.
In 1486, Cristina came to Venice to visit the Carneval. Leonardo informed Ezio of her arrrival, who then disguised as her husband and stole her a kiss.
When Cristina discovered it was actually Ezio, she got angry, both because she was a married woman and because they haven't met in so long. But she does admit that she loved him and would have rather married him than Manfredo, but also adds that it's too late now. She tells him to never seek her again, and storms away.
After Lorenzo de' Medici's death in 1494, Girolamo Savonarola takes control of Florence and starts the Falò delle vanità (Bonfire of the Vanities), the burning of objects that are deemed to be occasions of sin.
Because of their rich fineries, the home of Cristina and Manfredo was attacked by the fanatics following Savonarola. They killed Manfredo and chased after Cristina, who was able to escape at first, but was later cornered by them.
Ezio came to her aid, but she was already mortally wounded. Cristina showed him the pendant he had given her twenty-two years ago, and said she wished for another chance with him. She died in his arms.
Cristina is voiced by Amber Goldfarb.
Ezio briefly mentions Cristina in a letter to Claudia in Assassin's Creed: Revelations. He writes that "After the death of Cristina, something inside me withered."