Sedulius Scotus or Scottus (fl. 840–860) was an Irish monk, teacher, Latin grammarian, and scriptural commentator who lived in the 9th century. During the reign of the Emperor Lothair (840–855), he was one of a colony of Irish teachers at Liège. Sedulius is sometimes called Sedulius the Younger, to distinguish him from Coelius Sedulius (a 5th-century poet). The usual Irish form of the name is Siadhal, but he appears to have been called Suadbar.[1] It is quite probable that towards the end of his days he went to Milan, following the example of his countryman Dungal, who established a school at Pavia. When and where he died is unknown.