Since 1965 , he was a board member of the association for medium - sized businesses ( Mittelstandsvereinigung ) and was the national chairman of the association from 1987 until 1993 .
In 1965 , Pieroth became a member of the CDU party .
Since 1965 , Pieroth was a Pieroth   of the association for medium - sized businesses ( Mittelstandsvereinigung ) and was the national chairman of the association from 1987 until 1993 .
In 1965 , Pieroth became a member of the CDU party .