Because this was a crime new to the human race, nobody could purify Ixion and he wandered an exile. Zeus took pity on him and decided not only to purify Ixion, but to invite him to Olympus as a guest. Once in Olympus though, Ixion became so enamored of Hera, and he desired to sleep with her. Zeus did not believe that Ixion would be so disrespectful as to have designs upon the wife of his host. To see if the rumors were true, Zeus made an image of Hera out of a cloud, and impregnated it. The cloud bore Ixion the monster Centaurus, who was unloved by the Graces and had no honor among men or the gods. Centaurus then mated with the mares of Mt. Pelion in Magnesia, and so from Ixion the race of centaurs was born.
To punish him, Zeus bound Ixion to a winged (sometimes flaming) wheel, which revolved in the air in all directions. Also, by order of the gods, Ixion was forced to call out continuously call out: "You should show gratitude to your benefactor." Ixion became one of the more famous sinners on display on Tartarus, and most writers mention him when describing the place. For example, Ovid wrote of him, and Vergil, with his moralistic interpretation of how sin should be punished, awards Ixion a special mention in the Aenead.
The focus of Ixion's mythology on the guest/host relationship shows the venerable age of Ixion's story. Of all the attributes Zeus became associated with, he was originally particularly worried that the custom of Xenia, the formal institution of friendship that ensured traveling archaic Greeks could count on each other for safety in antiquity, be enforced (for more on this in all the Greek world see Powell 150; the importance of the guest/host relationship is fundamental to all world mythology, take the Biblical story of Sodom and Gommorah, for example).
Aeschylus remembered Ixion's role as the purified progenitor of blood guilt in the Euminides. Athena, before she will hear Orestes' case refers to him as Ixion, an allusion Orestes balks at and tries to convince her is false (Euminides. 450-455).
Pirithous, king of the Lapiths, good friend of Theseus, and important in later myth, is considered to be one of Ixion's children. There is another claimant to Pirithous' paternity though. Zeus, in the Iliad 14. 317-318, claims to have seduced Dia, Ixion's wife, and fathered Pirithous.