Schubert's first piano sonata, composed at the age of 18. Like the Second Sonata, composed around the same period, it is a three-movement sonata lacking a fourth movement. Prior to this, he had attempted the Sonata D 154, but it remained unfinished. While its form adheres to the classical sonata framework, Schubert's unique sensibility is already evident, particularly in the handling of chords in the second movement, marking it as a work that opens the door to the Romantic era.