Aino

Aino ("the only one") is a character in the Kalevala. She is Joukahainen's sister. She appers in poems three, four and five.

Joukahainen loses a spell singing match to Väinämöinen, whose spells get Joukahainen stuck in a bog. In order to get out from the bog, Joukahainen promises his sister to Väinämöinen as a wife as his last resort. When Joukahainen and Aino's mother hears of this, she is delighted to get such a great man to the family. However, Aino is horrified to end up as a wife to an old man, and drowns herself as the väki of water call for her. Väinämöinen tries to catch Aino but only gets a strange fish. He tries to cut the fish to pieces in order to eat it but it jumps into the water and tells that it used to be Aino.

After this Väinämöinen forbids the coming generations from marrying anyone significantly younger, or getting married at a young age.

Creation of Aino
Aino as a character does not exist in Finnic folk poetry but is a creation of Elias Lönnrot, the compiler of Kalevala. Her story is based on multiple poems that were originally not connected to each other in any way.

First inspiration for Aino comes from the poem Hirttäytyneen neidon runo (Poem of the maiden who hanged herself). In the poem a young maiden goes to the forest to make bath brooms when she encounters a suitor. She gets scared and runs back home crying. She tells everyone it is because she lost her jewellery, but reveals the truth of the encounter to her mother. The mother tells the girl to prepare herself for this suitor. Instead, the girl goes to a granary and hangs herself. The story has been interpreted to imply that the girl was sexually assaulted by the suitor in the forest. The girl lost her virginity to the man and was therefore unfit to marry anyone else. The possibility of a good life and marriage was taken from her, which is why she commits suicide.

Another story that worked as an inspiration was Vellamon neidon onginta (Fishing of a maiden of Vellamo). In it Väinämöinen catches a strange fish he tries to eat but the fish jumps back into the water. It reveals to be a girl turned into a fish and mocks Väinämöinen for not noticing this. These two stories and some other poems of the worries of young women were combined in order to create the character of Aino.

Aino as a name
It has been speculated that a character named "Aino" didn't exist before the writing of Kalevala. Kalevalan poems speak of "aino sisko" (the only sister) and "aino tyttönen" (the only girl/daughter), which could be a reference to the only sister or girl child in the family. There is an assumption that Elias Lönnrot turned "aino" into a proper noun by capitalizing it. Nevertheless, after the publication of Kalevala Aino has become one of the most popular names for girls in Finland.