In the Baroque period, music in C minor was usually written with a two-flat key signature. When this music is printed today, sometimes it is still printed in the same way.
C minor has had the meaning of heroicstruggle from Beethoven's time and the composer wrote many of his most emotional, dramatic works in this key. This has also been done by many others, following Beethoven's style.
These are just a few of the well-known works to be written in C minor: