Considered classics of Marxist/Socialist thought, these books are mostly forgotten today, and the English-language editions published at the beginning of the 20th Century have only recently become available through large-scale digitization projects of Public Domain books. Daniel DeLeon, leader of the Socialist Labor Party of America and translator of this series into English, writes a Preface to each volume as an introduction. The Abbatial Crosier is set in the year 719 when Germanic Franks under the leadership of Charles Martel (The Hammer) are driving back invading Moslems. The native Gauls are enslaved by both sides of the conflict. Sue quotes a female slave as saying "Sad days these are for us. We have only the choice of servitudes.
