As soon as the Czech people were allowed to produce plays and operas in their own language Smetana thought it was his duty to write a series of nationalist operas. His operas were based on the nation’s history and legends. His symphonic cycle "Ma Vlast" was programme music, full of heroism, often describing nature and the countryside. Smetana also wrote a lot for piano. He was the most important Czech composer there had been at that time. Smetana and Dvořák were the founders of modern Czech music.