Early life[]
Guglielmo de' Pazzi is a member of the Pazzi family. He is the younger brother of Francesco de' Pazzi and shares a very strong brotherly bond with him despite his loyalties to their rivals Medici. His parents died young which left him in the hands of his uncle Jacopo de' Pazzi. In childhood, his father desired peace between the Medici and Pazzi which led to an arranged marriage between Guglielmo and Bianca de' Medici. Once his father died, Jacopo broke off their engagement, but his love for Bianca remained unchanged until they were adults.
Old scores[]
Bianca is shown secretly writing and meeting Guglielmo, without the knowledge of both of their families.
After an assassination attempt on Piero de' Medici, his sons start to search for the culprit and soon discover Jacopo de' Pazzi's involvement leading them to accuse him in the Priori. However, as promised Guglielmo gathers the evidence to prove his uncle's innocence, thus charging him free of guilt in the Priori.
Standing alone[]
Now that Lorenzo had taken his father's position without his proper consent, Bianca and Guglielmo hope for the feuds of their families to end as they both believe Lorenzo to be someone preferring peace.
Later, while his uncle Jacopo and brother Francesco plot against Lorenzo's visit to Rome, Guglielmo implored them to be peaceful with the Medici but was dismissed by his uncle who wished the Medici dissolved.
Later, when a joust contest is held, Guglielmo stands against Giuliano, however the contest was drawn up due to Giuliano deliberately not defeating Guglielmo as he knew him being involved with his sister Bianca.
Obstacles and opportunities[]
When Lorenzo betroths her with Bastiano Soderini to enhance his bankable benefits, Bianca runs away with Guglielmo. He takes her virginity to make them betrothed before God. With news of this, Lorenzo goes to make a deal with Jacopo to officially arrange a marriage union between Guglielmo and Bianca. Jacopo however agrees reluctantly, but when he learns of Guglielmo's true loyalties towards the Medici family he disowns him as a Pazzi, thus leading to a rivalry with his other nephew Francesco who happens to have great concern for his younger brother.
Blood with blood[]
With getting married to Bianca, now Guglielmo leads a prosper happy life with her, and also arranges a marriage union of his elder brother Francesco with Novella Foscari.
Ties that bind[]
Bianca gives birth to a daughter named Contessina de' Pazzi, while on the other side Guglielmo's brother Francesco has a furious argument with Lorenzo and also sends his wife Novella Foscari back to Venice.
Betrayal[]
While planning to murder the Medici brothers, Francesco de' Pazzi tries to intimidate Guglielmo by inviting him somewhere to meet in person, but Guglielmo decides not to and thus he and Bianca remained unaware of the Pazzi Conspiracy.
Mass[]
After the events of the Pazzi Conspiracy result in Giuliano de' Medici's brutal killing, Lorenzo tries to kill Guglielmo out of rage but he was defended by Bianca and Clarice. Guglielmo being a Pazzi but also not involved in the conspiracy was spared a death sentence but was banished from Florence by Lorenzo. Bianca, out of love for Guglielmo , abandons her family and leaves with him.