Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Name the reason for 20 july 1031

### Inputs:
table_name: table, columns: ['Co-king', 'Relationship to Monarch', 'Crowned', 'Co-kingship ceased', 'Reason', 'Monarch']

### Response:
SELECT Reason FROM table WHERE Co-kingship ceased = 20 July 1031