Solveig : is a lovely pure young girl who falls in love with Peer. When he finally returns to her, her love is maternal and forgiving. 

On his way to the western coast, Ibsen travelled through the Gudbrandsdalen valley and over the Sognefjell mountains. He walked through the region where the stories about the local legend Per Gynt originate, and he might have been told these folk tales on this part of the journey. 

At the wedding, the other guests taunt and laugh at Peer, especially the local blacksmith, Aslak, who holds a grudge after an earlier brawl. In the same wedding, Peer meets a family of Haugean newcomers from another valley. He instantly notices the elder daughter, Solveig, and asks her to dance. She refuses because her father would disapprove, and because Peer's reputation has preceded him. She leaves, and Peer starts drinking. When he hears the bride has locked herself in, he seizes the opportunity, runs away with her, and spends the night with her in the mountains.

He comes across a woman clad in green, who claims to be the daughter of the troll mountain king. Together they ride into the mountain hall, and the troll king gives Peer the opportunity to become a troll if Peer would marry his daughter. Peer agrees to a number of conditions, but declines in the end. He is then confronted with the fact that the green-clad woman is with child. 

He then meets one of the most interesting characters, the Bøyg — a creature who has no real description. Asked the question "Who are you?" The Bøyg answers, "Myself".

Upon awaking, Peer is confronted by Helga, Solveig's sister, who gives him food and regards from her sister. Peer gives the girl a silver button for Solveig to keep and asks that she not forget him.

This is the green-clad woman from the mountain hall, and her half-human brat is the child begotten by Peer from his mind during his stay there. She has cursed Peer by forcing him to remember her and all his previous sins, when facing Solveig. Peer hears a ghostly voice saying, "Go roundabout, Peer", and decides to leave. He tells Solveig he has something heavy to fetch. He returns in time for his mother's death, and then sets off overseas.

His companions rob him, after he decides to support the Turks in suppressing a Greek revolt, and leave him alone on the shore. 

Then he decides to become a historian and travels to Egypt. As he addresses the Sphinx, believing it to be the Bøyg, he encounters the keeper of the local madhouse, himself insane, who regards Peer as the bringer of supreme wisdom. Peer comes to the madhouse and understands that all of the patients live in their own worlds, being themselves to such a degree that no one cares for anyone else. In his youth, Peer had dreamt of becoming an emperor. In this place, he is finally hailed as one—the emperor of the "self". 

Back home in Norway, Peer Gynt attends a peasant funeral and an auction, where he offers for sale everything from his earlier life. Peer stumbles along and is confronted with all that he did not do, his unsung songs, his unmade works, his unwept tears, and his questions that were never asked.

Peer escapes and is confronted with the Button-molder, who maintains that Peer's soul must be melted down with other faulty goods unless he can explain when and where in life he has been "himself". Peer protests. He has been only that, and nothing else. Then he meets the troll king, who states that Peer has been a troll, not a man, most of his life.

Peer despairs in the end, understanding that his life is forfeit; he is nothing. But at the same moment, Solveig starts to sing—the cabin Peer built is close at hand, but he dares not enter. The Bøyg in Peer tells him "go around". The Button-molder shows up and demands a list of sins, but Peer has none to give, unless Solveig can vouch for him. Then Peer breaks through to Solveig, asking her to forgive his sins. But she answers: "You have not sinned at all, my dearest boy."

Find out more in my enriched essay "Peer Gynt : a Norwegian Julien Sorel ?"