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_58173 ( "Heir" text, "Status" text, "Relationship to Monarch" text, "Became heir" text, "Reason" text, "Ceased to be heir" text, "Monarch" text )

### Question ###
Which Reason is given when 1103 is the date for Became heir?

### Accurate SQL ###

SELECT "Reason" FROM table_58173 WHERE "Became heir" = '1103'