Folke Filbyter is the popularized name of the pagan progenitor of the House of Bjälbo clan.[1] Since Folke is said to have been the great-great-grandfather of Birger Brosa, he would have lived in the 11th century.[1]
His cognomen Filbyter is believed to mean "foal biter" and refers to a man who castrates colts with his teeth.[1]