Kalevipoeg (Kalev's Son) is an epic poem by Friedrich Reinhold Kreutzwald held to be the Estonian national epic.
There existed an oral tradition within Ancient Estonia of legends explaining the origin of the world. Within old Estonian folklore, a malevolent giant by the name of Kalev, Kalevine, Kalevipoiss, Kalevine posikine and Kalevin Poika appears, battling with other giants or enemies of the nation. The earliest written references are found in Leyen Spiegel in 1641 as "Kalliweh", and in a list of deities published by Mikael Agricola in 1515 as "Calenanpoiat".
The main material is taken from Estonian folklore of a giant hero named Kalevipoeg ("Kalev's son", often Anglicised as "Kalevide"). These tales mainly interpret various natural objects and features as traces of Kalevipoeg's deeds and have similarities with national epics from neighbouring regions, especially the Finnish Kalevala, and also in Scandinavia.
In 1839, Friedrich Robert Faehlmann read a paper at the Learned Estonian Society about the legends of Kalevipoeg. He sketched the plot of a national romantic epic poem. In 1850, after Faehlmann's death, Kreutzwald started writing the poem, interpreting it as the reconstruction of an obsolete oral epic. He collected oral stories and wove them together into a unified whole.
The first version of Kalevipoeg (1853; 13,817 verses) could not be printed due to censorship. The second, thoroughly revised version (19,087 verses) was published in sequels as an academic publication by the Learned Estonian Society in 1857–1861. The publication included a translation into German. In 1862, the third, somewhat abridged version (19,023 verses) came out. This was a book for common readers. It was printed in Kuopio, Finland.