Gianni de' Soldanieri
Giani de 'Soldanier or Giovanni de Soldanieri' was an Italian politician, born in Florence to a Ghibelline family.
He is best known for being found in the 9th circle of hell, reserved for those who sin by treachery, by Dante in his epic Inferno.
I think Gianni de' Soldanier is farther on,with Ganelon and Tebaldello,
- più là con Ganellone e Tebaldello,
who opened up Faenza while it slept.
Historians hold that while serving as potesta or lord of Faenza, with the help of Tribadello di Zambrasi, he betrayed the town to the Guelfs of Bologna.