Excerpts from Books and Wikipedia
"A prominent general, Maurice fought with success against the Sasanian Empire. . . . The Romans were no longer obliged to pay the Persians thousands of pounds of gold annually for peace. Maurice campaigned extensively in the Balkans against the Avars – pushing them back across the Danube by 599. He also conducted campaigns across the Danube, the first Roman Emperor to do so in over two centuries. In the west, he established two large semi-autonomous provinces called exarchates, ruled by exarchs, or viceroys of the emperor. In Italy Maurice established the Exarchate of Italy in 584, the first real effort by the Empire to halt the advance of the Lombards. With the creation of the Exarchate of Africa in 590 he further solidified the power of Constantinople in the western Mediterranean. His reign was troubled by financial difficulties and almost constant warfare. In 602 a dissatisfied general named Phocas usurped the throne, having Maurice and his six sons executed. This event would prove a disaster for the Empire, sparking a twenty-six year war with Sassanid Persia which would leave both empires devastated prior to the Muslim conquests." [Wikipedia]