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_91 (ceased_to_be_duke_of_girona VARCHAR, heir_of VARCHAR)

### Question ###
WHAT IS THE Ceased to be Duke of Girona THAT HAS PETER IV?

### Accurate SQL ###

SELECT ceased_to_be_duke_of_girona FROM table_name_91 WHERE heir_of = "peter iv"