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_44 (tonnage__grt_ INTEGER, nationality VARCHAR, name VARCHAR)

### Question ###
Which Tonnage (GRT) has a Nationality of united kingdom, and a Name of king gruffydd?

### Accurate SQL ###

SELECT MIN(tonnage__grt_) FROM table_name_44 WHERE nationality = "united kingdom" AND name = "king gruffydd"