Ludwig van Beethoven
The last years were unhappy years for Beethoven. During this time he composed very little. Then, in 1817, he recovered and wrote his last two symphonies, a mass called Missa Solemnis, his last five piano sonatas, and a group of string quartets which were so modern and difficult that very few people at the time understood the music. Nowadays, people think they are the greatest works ever written for string quartet.