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

### Instruction:
Who is the Monarch whose Heir is Robert Curthose when the Reason is that the father became king?

### Inputs:
table_name: table, columns: ['Heir', 'Status', 'Relationship to Monarch', 'Became heir', 'Reason', 'Ceased to be heir', 'Monarch']

### Response:
SELECT Monarch FROM table WHERE Heir = robert curthose AND Reason = father became king