Severus of Antioch was the Patriarch of Antioch and a moderate Miaphysite. Sergius the Grammarian is a lesser-known figure, but the content of his letters demonstrates that he was a more extreme Miaphysite. The early 6th century correspondence between the two consists of a set of three letters apiece and an apology by Sergius. Made available in Syriac along with Torrance's translation, these letters are an important part of the working out of concerns associated with the Council of Chalecedon.