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.
Blastares was a hieromonk in the monastery of Kyr Isaac in Thessalonica, where he died after 1346.
[1] Apart from the Syntagma, Blastares was also the author of a number of other legal works, including a lexicon of Latin legal terms, and summaries of the nomocanons of Niketas of Heraclea, patriarchs Nikephoros I and John Nesteutes.
[2] His further work includes a poem on the offices and titles of the Byzantine court, a synopsis of rhetoric; theological treatises against the Latin Church, azymes, the Jews, and Palamism; a work on Divine Grace; a letter to Constantine II Lusignan on the Holy Spirit; as well as liturgical hymns and epigrams.