This is a study on El Greco’s Late Works and Byzantine Painting. El Greco is a Cretan-born painter who settled in Spain. He was known as El Greco (the Greek) but his real name was Domenikos Theotokopoulos (Δομίνικος Θεοτοκόπουλος) and it was thus that he signed his paintings throughout his life, always in Greek characters. Although little is known of his youth, a few works survive by him in the Byzantine tradition of icon painting, notably the discovered in 1983. El Greco was trained in the prevailing post-Byzantine style of Crete, and, though he subsequently adapted and ‘transformed’ what he had learned on moving to Italy, this background remained fundamental to him and it almost certainly influenced the unique style that he forged in the later part of his career in Spain. He occasionally continued to use compositional schemes and formal or iconographic motifs that originated in Byzantine painting in his mature work. In such art there is no concern with optical observation, either empirical or scientific. Its purpose is to convey the transcendental world of the figures represented, rather than natural phenomena as perceived by the senses. El Greco’s interests in theology, liturgy and hagiography, combined with philosophy, history and literature, are reflected by the inventory of his library. The treatises on painting, sculpture and architecture to which Pacheco refers are lost, but further important evidence has been discovered which vividly conveys El Greco’s ideas, at least at one particular period of his development. This is the annotations on his copies of Vasari’s Lives and Daniele Barbaro’s edition of Vitruvius’ Ten Books on Architecture. It becomes clear that El Greco held trenchant opinions about style and the nature of art and architecture. He is actually a learned painter and a theorist. Surely, while he stayed in Italy, Venice and Rome, at most for 9 years(1567-1576), he rapidly assimilated into artists of Renaissance and Mannerism, especially Titian, Tintoretto, Michelangelo. But El Greco’s late works gradually turn into stylistic development after 1580’ s mid. Remarkably, the brushwork is more vigorous ; light is bleached white and fitful, colours are pure, luminous and vibrant. As they glow with unearthly beauty, figures are more elongated, dematerialised and dynamically charged. There is a new spiritual energy. These metaphysical light and abstracted form reveal unequivocally that the mystical imagery of his late style was personal to him and Byzantine painting. Moreover, the image that emerges in his work is illuminated, dematerialized and flame-like. Occasionally, his treatment of light, colour and form reflected the concepts of Christian Neo-Platonism.