According to a tradition recorded by early commentators on Dante's Divine Comedy, she can be identified as the 'Pia' mentioned in Canto V of Purgatory, where Dante and Virgil meet those were penitent at the time of their sudden violent deaths – her tale follows that of Bonconte da Montefeltro. She states that she came from Siena and was killed by her husband in the Maremma: She refers bitterly to her murderer for his disregard of his marital vows to her and briefly tells Dante her story. She asks the poet – once he has rested from his long journey – to remember her among the living and thus speed her journey through Purgatory. Dante uses the name 'la Pia' not 'Pia', underlining the familiarity between them. She also asks him to pray for her since she knows none of her family do so. The identification of this 'Pia' with Pia de' Tolomei is now almost universally accepted, although conclusive documentary proof of this has yet to be found. Early commentators on the poem noted that she was to be identified as a woman of the Tolomei family in Siena, wife of Nello dei Pannocchieschi, lord of Castel di Pietra in Maremma, podestà of Volterra and Lucca, captain of the Guelph Taglia from 1284 and alive until at least 1322. There is also a surviving record of his second marriage, as a widower, to Margherita Aldobrandeschi, countess of Sovana and Pitigliano. They had one son, Binduccio or Bindoccio, who was murdered, aged thirteen, when Orsini assassins, threw him down a well in Massa Marittima. The surviving archives do not name Nello's first wife, but she has been identified as Pia. Nello owned Castel di Pietra in Maremma, where it has been suggested he murdered Pia in 1297, either after she found out he was having an affair with Aldobrandeschi or to clear the way for his second marriage. Among the early commentators, Jacopo della Lana, l'Ottimo and Francesco di Bartolo claim that she may have been killed for some crime, while Benvenuto and an anonymous Florentine of the 14th century assert it was due to her husband's jealousy. Against this identification, the Tolomei family had no daughters or nieces named Pia in Nello's time. However, one male of the family did marry a woman named Pia Malavolti – the marriage did not last long and so the Tolomei decided to have Nello, the head of the family, remove her to Maremma, where she died in misery, possibly murdered. A closely related theory is that Pia was born a Malvoti and entered the Tolomei family by her marriage to Baldo d'Aldobrandino de' Tolomei. According to this story, Pia was accused of adultery by her husband, then kidnapped by Nello and taken to Maremma, where she died.
Pia de' Tolomei. Composizione in ottava rima secondo la tradizione cantata, re-issue of the short poem by Giuseppe Moroni, known as il Niccheri, edited by Guglielmo Amerighi
