Ludwig Van Beethoven's string quartets were written over a long period of his life, spanning from 1799 to 1826. The tragedies that occurred throughout the Beethoven's life did not prevent him from writing these seventeen masterpieces. String quartets can be divided into three periods; beginning middle and end with the first six quartets of op. 18 marking his “early” works. As Beethoven's writing began to blossom with creativity and imagination, he wrote the "Rasumovsky" quartets which mark the "middle" period of his career. Finally, the late quartets (also the last works written by Beethoven) provide a cornerstone for various composers writing string quartets throughout the Romantic era and into the 20th century, notably using counterpoint and harmony. This essay will show how these works were of great importance in the development of the string quartet throughout Beethoven's career, and also how their influences can be found in the string quartets of other composers. In Beethoven's early quartets he drew heavily from both Mozart and his tutor, Joseph Haydn. Before Beethoven wrote his first quartet, he had already written several different compositions because he first really wanted to establish his own style of writing. Op. 18, No. 1 in F, was written for the first time in 1799 but still remains close to the writing style of the Haydnesque and Mozartian quartet, but the young Beethoven begins to fit into his own ideas. This is evident from the very first movement (see example 1). Example 1 – Beethoven, Op. 18, No. 1, Allegro con brio, bar 13. Here, Beethoven takes melodic expression to a new level: the appoggiatura of measures 14 and 16 creates harmonic tension over a diminished seventh chord that creates "the very expressive progression used by XIX-...... middle of paper ......es in the opening of the last movement. Additionally, the decrease in line count and momentum can be compared to the long tonic octave at the end of the fugue in Op. 133. It is clear that Beethoven played an important role in the development of the string quartet, largely in terms of creativity and innovation. His early quartets show great influence from those of the classical period and, along with his, they influenced his contemporaries and later composers. The quartets published later in his life demonstrate even greater imagination and use of expression. It was also through similar uses of texture, harmony, rhythm and counterpoint that composers of the Romantic period and the 20th century wrote their own string quartets. Those of Beethoven, however, represent considerable progress in the way the string quartets are written and in the intensity of the emotions they convey.Bibliography