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_30429 ( "Emperor" text, "Heir" text, "Relationship to emperor and status" text, "Became heir" text, "Ceased to be heir" text, "Next in line" text )

### Question ###
How many next in lines had heirs of Archduke Karl?

### Accurate SQL ###

SELECT COUNT("Next in line") FROM table_30429 WHERE "Heir" = 'Archduke Karl'