Henrik Ibsen was a Norwegian playwright who is considered one of the most influential figures in modern theater. He is known for his realistic and often controversial plays that addressed social and moral issues. Some of his most famous works include "A Doll's House," "Hedda Gabler," and "Ghosts." Ibsen's plays challenged the conventions of his time and continue to be studied and performed around the world. His contributions to the development of modern drama have had a lasting impact on the theatrical landscape.