Johann Christian Bach (September 5, 1735 – January 1, 1782) was a German composer of the Classical era, the eighteenth child of Johann Sebastian Bach, and the youngest of his eleven sons. After living in Italy for several years, Bach moved to London in 1762, where he became known as "the London Bach". He is also sometimes known as "the English Bach", and during his time spent living in the British capital, he came to be known as John Bach. He is noted for playing a role in influencing the concerto styles of Haydn and Mozart. He contributed significantly to the development of the new sonata principle.