Theophylact Simocatta (Byzantine Greek: Θεοφύλακτος Σιμοκάτ(τ)ης Theophylaktos Simokat(t)es; Latin: Theophylactus Simocatta) was an early seventh-century Byzantine historiographer, arguably ranking as the last historian of Late Antiquity, writing in the time of Heraclius (c. 630) about the late Emperor Maurice (582–602).
Simocatta is best known as the author of a history in eight books, of the reign of the emperor Maurice (582–602), for which period he is the best and oldest authority. However, his work is of lesser stature than that of Procopius and his self-consciously classicizing style is pompous, but he is an important source of information concerning the seventh-century Slavs, the Avars and the Persians, and the emperor's tragic end. He mentions the war of Heraclius against the Persians (610–28), but not that against the Arabs (beginning 634), so it is likely that he was writing around 630. Among his sources he used the history of John of Epiphania.
Edward Gibbon wrote:
His want of judgement renders him diffuse in trifles and concise in the most interesting facts.
Nicolaus Copernicus translated Greek verses by Theophylact into Latin prose and had his translation, dedicated to his uncle Lucas Watzenrode, published in Kraków in 1509 by Johann Haller. It was the only book that Copernicus ever brought out on his own account.
In regards to the Far East, Simocatta wrote a generally accurate depiction of the reunification of China by Emperor Wen (r. 581-604 AD) of the Sui Dynasty, with the conquest of the rival Chen Dynasty in southern China, correctly placing these events within the reign period of Byzantine ruler Maurice. Simocatta also provided cursory information about the geography of China along with its customs and culture, deeming its people "idolatrous" but wise in governance. He also related how the ruler was named Taisson, the meaning of which was "Son of God", possibly derived from Chinese Tianzi (Son of Heaven, a title of the emperor of China) or even the name of the contemporaneous ruler Emperor Taizong of Tang.