Complex sentence: He wrote the words of the Estonian national anthem, "Mu isamaa, mu õnn ja rõõm", and was the father of the poet Lydia Koidula.
Split into simpler sentences: He wrote the words of the patriotic song "Mu isamaa, mu õnn ja rõõm", which later became the national anthem of Estonia. He was the father of the poet Lydia Koidula.