Barlaam of Calabria was a 14th-century monk and theologian known for his role in the Hesychast Controversy, a theological dispute within the Eastern Orthodox Church. He was originally from Calabria, Italy, and became a prominent figure due to his opposition to the mystical practices of Gregory Palamas, who advocated for the experience of God's uncreated light. Barlaam's teachings emphasized the importance of reason and philosophy in understanding faith, contrasting with the experiential approach of his opponents. His writings, which included critiques of Palamism, contributed to the intellectual debates of the time and influenced the development of Orthodox theology.