Complex sentence: In 1216, the brother of Helena was made King John I of Sweden, and wheh he died childless in 1222, lady Helena and her daughters were made heirs of the Sverker dynasty.
Split into simpler sentences: In 1216, the brother of Helena was made King John I of Sweden. When her brother king John died childless in 1222, lady Helena and her daughters were made heirs of the Sverker dynasty.