Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_21 (battle VARCHAR, bulgarian_commander VARCHAR)
### Question:
What is the Battle with Bulgarian Commander Ivan Asen II?
### Answer:
SELECT battle FROM table_name_21 WHERE bulgarian_commander = "ivan asen ii"