Justinian's rise to imperial power began in 527 with his appointment as co-emperor to Justin I, his uncle, who died later that same year. His sole rule was characterized by profound efforts to strengthen the empire and return the state to its former ancient glory. To this end, Justinian drew upon administrators and counselors from outside the aristocratic class. His own modest origins, along with his selection of these court members, contributed to lasting tensions with the Byzantine nobility. This situation was exacerbated by Justinian's authoritarian approach to governance, and his pronouncement that the emperor's will was law further undermined the authority of the city's senate as well as its factions. In the religious sphere, Justinian took a leading role in shaping church policy. As an adamant defender of Christian Orthodoxy, he fought to extinguish the last vestiges of Greco-Roman paganism, to root out Manichaeans and Samaritans, and to oppose competing Christian sects, including the Arians and the Monophysites. Justinian also came into direct conflict with the papacy in 543, further straining relations between the western and eastern territories of his empire.
He extended Byzantine teritory and influence,his building programme (which included the Hagia Sophia) gave not just Constantinople but all the areas under Byzantine control beautiful churches (and as a byproduct spread Byzantine building technology),and his Justinian Code is still the basis of many legal codes today. The main criticism of Justinian is that the territories he conquered in Western Europe were unsustainable in the long run,and holding and defending them drained money and military resources from future emperors.
He extended Byzantine teritory and influence,his building programme (which included the Hagia Sophia) gave not just Constantinople but all the areas under Byzantine control beautiful churches (and as a byproduct spread Byzantine building technology),and his Justinian Code is still the basis of many legal codes today. The main criticism of Justinian is that the territories he conquered in Western Europe were unsustainable in the long run,and holding and defending them drained money and military resources from future emperors.