Franz Schubert’s Piano Sonata op. 143 in a minor was composed in February 1823 following his large “Wanderer Fantasy”. With its formal coherence and mature originality, the a-minor Sonata initiated a new phase in Schubert’s sonata oeuvre. The composition avoids any superficial virtuosity, but nevertheless places great technical demands on the performer. At the same time, the richness of colour and sonority are triumphant to such an extent that the work is one of Schubert’s most frequently performed sonatas. The autograph was available as the definitive source for Henle’s revision of the Urtext edition; a contemporary copyist’s manuscript and the posthumous first edition were consulted for the purpose of comparison. In her preface, Schubert researcher Andrea Lindmayr-Brandl presents the current state of research. This new edition also contains fingerings by the well-known Schubert interpreter Martin Helmchen.