Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_26 (spouse VARCHAR, father VARCHAR)

### Question ###
Leopold VI, Duke of Austria is the father-in-law of which person?

### Accurate SQL ###

SELECT spouse FROM table_name_26 WHERE father = "leopold vi, duke of austria"