Frederic Chopin had written polonaises since age 7, and he had put all of them in the desk drawer, where they would remain until after his death. His judgment was quite good, as the early polonaises gave a hint of what would come, but what was not yet there. Now in 1835, at age 25, Fred produced a pair of mature polonaises that was good enough to publish. They have become standards of the repertory.
Chopin: Polonaise in C# minor, Op. 26/1
Chopin: Polonaise in E-flat minor, Op. 26/2