The Sonata, Op. 12 is the largest of Sibeliuss piano works. Sibelius may have composed it in the summer of 1893. The second movement comes from a work originally planned for male choir to a text from the Finnisch national epic Kalevala. Something of its character my still have shaped the final outcome, with its restless opening bars, sparkling writing in the pianos high register, the calming homophonic passages, and soothing arpeggio writing.
The first public performance took place on April 17, 1895, in the Solennity Hall of Helsinki University. The first edition was published by Breitkopf & Härtel in 1906.