Matthew Blastares (Greek: Ματθαῖος Βλαστάρης or Βλάσταρις, romanized: Matthaios Blastares/Blastaris; fl. 1335–1346) was a 14th-century Byzantine Greek monk in Thessalonica and early scholarly opponent of reconciliation with Rome. He was also the writer of the Syntagma Canonum.
He is best known for his Syntagma kata stoicheion (lit.'Alphabetical Treatise'), completed in 1335.[1] The chief innovation of the Syntagma was Blastares' ambition was to reconcile canon law with civil law, whereas previous treatises had focused on one of the two, ignoring the other.[1]
The Syntagma is subdivided into 24 sections, each on a specific legal topic, and usually further subdivided into chapters.[1] It became very popular even outside the Byzantine Empire, and was translated into Serbian during the Serbian Empire of Stephen Dushan.[1]