Ludwig van Beethoven

A piano sonata is a sonata written for unaccompanied piano.
Piano sonatas are usually written in three or four
movements, although piano sonatas have been written with
one movement (Scarlatti, Scriabin), two movements
(Beethoven), five (Brahms' Third Piano Sonata) or even
more movements. The first movement is usually composed
in sonata form.

Piano sonatas in the Classical era :

Although various composers in the 17th century had written
Piano pieces which they entitled "Sonata", it was only in the
classical era, when the piano displaced the earlier
harpsichord and sonata form rose to prominence as a
principle of musical composition, that the term "piano
sonata" acquired a definite meaning and a characteristic
form.

All the well-known Classical era composers, especially
Joseph Haydn, Muzio Clementi, Wolfgang Amadeus Mozart,
and Ludwig van Beethoven, wrote many piano sonatas.
Muzio Clementi wrote more than 110 piano sonatas. He is
well-known as the "The Father of the Pianoforte".
Clementi's Op.2 is the first real piano sonata. The much
younger Franz Schubert also wrote many. The 32 sonatas of
Beethoven, including the well-known Pathétique Sonata and
the Moonlight Sonata, are often considered the pinnacle of
piano sonata composition.