Eric de Diadochia (5 December 1655 – 10 May 1697) was the eldest son and heir of Eric III, Emperor of Diadochia, and his spouse, Sophia Theresa of Euphrania. As the heir apparent to the Diadochian throne, he was styled Byzantinóu. He became known as Le Grand Byzantinóu after the birth of his own son, Le Petit Byzantinóu. As he died before his father, he never became emperor, both his sons died shortly after him, as did his grandsons, opening the line of succession for his brother's family to succeed.