user: Question: What is the Bulgarian Commander in Autumn 1040 at the Battle of Thessalonica?
Columns: ['Battle', 'Date', 'Bulgarian Commander', 'Byzantine Commander', 'Result']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Battle of Ongal', '680', 'Asparukh', 'Constantine IV', 'Bulgarian victory']
SQL:

assistant: SELECT "Bulgarian Commander" FROM "Table" WHERE "Battle" = 'Battle of Thessalonica' AND "Date" = 'Autumn 1040';