[1] Blanche was the daughter of King Charles II of Naples and Mary of Hungary.

[2] Among her siblings were King Robert I of Naples, Saint Louis of Toulouse, Philip I of Taranto (titular Emperor of Constantinople), Charles Martel of Anjou (titular King of Hungary), Queen Eleanor of Sicily, and Queen Maria of Majorca.

Her father was helping him defend Montferrat, hoping to make John his vassal.

The new Pope Boniface VIII, elected in 1294 at Naples under the auspices of King Charles, mediated between the latter and James II of Aragon,[3] and the Treaty of Anagni was signed: James was to marry Blanche and was promised the investiture, by the pope, of Sardinia and Corsica, while he was to leave the Angevin a free hand in Sicily and even to assist him if the Sicilians resisted.

Her death was probably linked to the birth of her daughter Violante, who was born in October 1310.