The seventh circle houses the violent. Its entry is guarded by the Minotaur, and it is divided into three rings:
      Outer ring: This ring houses the violent against people and property. Sinners are immersed in Phlegethon, a river of boiling blood and fire, to a level commensurate with their sins: Alexander the Great is immersed up to his eyebrows, although Dante praises Alexander at other points in the poem, meaning he might be referring to a different Alexander. Dionysius I of Syracuse, Azzolino da Romano, Guy de Montfort, Obizzo d'Este, Ezzelino III da Romano, Rinier da Corneto, and Rinier Pazzo are also seen in the Phlegethon as well as references to Atilla the Hun. The Centaurs, commanded by Chiron and Pholus, patrol the ring, shooting arrows into any sinners who emerge higher out of the river than each is allowed. The centaur Nessus guides the poets along Phlegethon and across a ford in the widest, shallowest stretch of the river (Canto XII). This passage may have been influenced by the early medieval Visio Karoli Grossi.

      The Gianfigliazzi family was identified by a heraldic device of a lion (blue on yellow background).
      Middle ring: In this ring are suicides and profligates. The suicides – the violent against self – are transformed into gnarled thorny bushes and trees and then fed upon by Harpies. Dante breaks a twig off one of the bushes and from the broken, bleeding branch hears the tale of Pietro della Vigne, who committed suicide after falling out of favour with Emperor Frederick II (his presence here, rather than in the ninth circle, indicates that Dante believes that the accusations made against him were false). Also here are Lano da Siena and Jacopo da Sant' Andrea. The trees are a metaphor for the state of mind in which suicide is committed. Dante learns that these suicides, unique among the dead, will not be corporally resurrected after the final judgement since they gave away their bodies through suicide; instead they will maintain their bushy form, with their own corpses hanging from the thorny limbs. The other residents of this ring are the profligates, who destroyed their lives by destroying the means by which life is sustained – i.e., money and property. They are perpetually chased and mauled by ferocious dogs. The destruction wrought upon the wood by the profligates' flight and punishment as they crash through the undergrowth causes further suffering to the suicides, who cannot move out of the way (Canto XIII).
      Inner ring: Here are the violent against God (blasphemers) and the violent against nature (sodomites and, as explained in the sixth circle, usurers). All reside in a desert of flaming sand with fiery flakes raining from the sky, a fate similar to Sodom and Gomorrah. The blasphemers lie on the sand, the usurers sit, and the sodomites wander about in groups. Dante sees the classical warrior Capaneus there, who for blasphemy against Zeus was struck down with a thunderbolt during the Siege of Thebes. Dante converses with two Florentine sodomites from different groups. One of them is Dante's mentor, Brunetto Latini; Dante is very surprised and touched by this encounter and shows Brunetto great respect for what he has taught him ("you taught me how man makes himself eternal; / and while I live, my gratitude for that / must always be apparent in my words"), thus refuting suggestions that Dante only placed his enemies in Hell. The other sodomite is Iacopo Rusticucci, a politician, who blames his wife for his fate. Those punished here for usury include the Florentines Catello di Rosso Gianfigliazzi, Guido Guerra, Iacopo Rusticucci, Ciappo Ubriachi, and Giovanni di Buiamonte; and the Paduans Reginaldo degli Scrovegni and Vitaliano di Iacopo Vitaliani. They are identified not primarily by name but by heraldic devices emblazoned on the purses around their necks, purses which "their eyes seemed to feast upon" (Cantos XIV through XVII).

Taken from Dante's Inferno on Wikipedia