did he participate in battles?
Yes, against the Sassanid Empire, and later against Italy were the major ones
Justinian I
From his uncle, Justinian inherited ongoing hostilities with the Sassanid Empire. In 530 the Persian forces suffered a double defeat at Dara and Satala, but the next year saw the defeat of Roman forces under Belisarius near Callinicum. Justinian then tried to make alliance with the Axumites of Ethiopia and the Himyarites of Yemen against the Persians, but this failed. When king Kavadh I of Persia died (September 531), Justinian concluded an "Eternal Peace" (which cost him 11,000 pounds of gold) with his successor Khosrau I (532). Having thus secured his eastern frontier, Justinian turned his attention to the West, where Germanic kingdoms had been established in the territories of the former Western Roman Empire.
which region was part of the eastern roman empire The extent fluctuated, but at its peak, it stretched from Byzantium up to Syria and Italy and North Africa, how would you define this type of empire? Romano-Hellenistic who are some of the rulers during this period? Justinian I, Constantine, Julian, Theodosius I to name a few what languages were spoken in the eastern region during this period? Primarily Greek, but Latin was introduced later what was this period's contribution in the fields of science and medicine? In the field of engineering Isidore of Miletus, the Greek mathematician and architect of the Hagia Sophia, produced the first compilation of Archimedes' works; Pendentive architecture, a specific spherical form in the upper corners to support a dome, is a Byzantine invention; A mechanical sundial device using the Antikythera mechanism was reactivated what were the musical instruments used during this period? Lyra, organ, aulos, oud etc. you had mentioned some rulers who controlled that empire, when years did the first ruler exercised power over the empire? From 527 to 565 CE what were some of his contributions during his ruling? Territorial expansion to include areas from the Western Roman Empire, conquering the Ostrogothic kingdom and the Iberian peninsula, engaging with the Sassanian Empire, uniform rewriting of Roman law, the "Corpus Juris Civilis", and construction projects such as the Hagia Sophia
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Justinian I [SEP] War with the Sassanid Empire, 527–532
From his uncle, Justinian inherited ongoing hostilities with the Sassanid Empire. In 530 the Persian forces suffered a double defeat at Dara and Satala, but the next year saw the defeat of Roman forces under Belisarius near Callinicum. Justinian then tried to make alliance with the Axumites of Ethiopia and the Himyarites of Yemen against the Persians, but this failed. When king Kavadh I of Persia died (September 531), Justinian concluded an "Eternal Peace" (which cost him 11,000 pounds of gold) with his successor Khosrau I (532). Having thus secured his eastern frontier, Justinian turned his attention to the West, where Germanic kingdoms had been established in the territories of the former Western Roman Empire.