Frederick I, Holy Roman Emperor
Bligger I was first mentioned in a document from 1142 as "bliggerus de steinahe". In 1150, Bligger's brother, was named Konrad I bishop of Worms. In 1171, Bligger was sent to Constantinople by Frederick I, Holy Roman Emperor to seek a bride for Frederick's son, Henry VI. There are indications that Bligger's son, Bligger II, and his brother Konrad accompanied him.