Bernard III was the son of Lord Herman II and his wife, Oda of Tecklenburg.
His father fell in battle in 1229, and Bernard III succeeded him as Lord of Lippe.
Via his brother, Bishop Simon I of Paderbron he acquired furthers offices, and reorganized the church in his principality.
He also fought feuds against the cities of Ravensberg and Sternberg, and against the House of Waldeck.
She was the daughter of Count Gottfried II of Arnsberg and Rietberg and his wife Elisabeth.