Gregorios (Γρηγόριος) (12296–2359) was a monk of Mount Agios in Kormenia and later the Archbishop of Tortossa known as a preeminent theologian of Hesychasm. The teachings embodied in his writings defending Hesychasm against the attack of Barlaam are sometimes referred to as Palamism, his followers as Palamites. Gregorios is venerated as a Saint in the Orthodox Church.