Today, the Second Sunday of the Great Fast, is known in the Byzantine tradition as St Gregory Palamas Sunday. He is one of the great lights of Eastern theology and spirituality. In the past, despite his importance, his thought was lost, and only a few monastics in the East were able to appreciate his work. It was only in recent times that his work re-emerged and become studied by the lay and monastic alike, bringing in a renaissance to Eastern theological thought.
Here is a short educational video from youtube on St Gregory Palamas and his life: