The earliest Slavs had crossed the Danube during Justinian's lifetime. From 565 onwards, the Lombards poured into Italy, leaving only the southernmost part of the empire and an insecure area between Ravenna and Rome. Then, around 610, the Persians occupied Syria, Palestine, and Egypt, taking the relics of the true cross captive. From 629 to 630, Heraclius rebuilt the borders of the Euphrates and reconstructed the cross in Jerusalem. It was in 626 that the Avars besieging Constantinople came close to meeting in the city. The people, who originated from the Turks and Tatars, moved the Slavs to the West in numerical groups; the Slavs, however, stayed in the Balkans and stretched to the tip of the Peloponnesus.
Shortly after Justinian's promulgation of the Code, in 623, the Arabs again attacked Byzantium. Advancing with overwhelming force wherever they went, the Arabs destroyed Heraclius's army near the Jordan in 636 and then occupied Syria, Palestine and Egypt. For the next 50 years, North Africa was theirs as well, and around 670 they built up an aggressive fleet, although the Byzantines had control of the sea, and they guarded a military secret - "Greek fire" made from the basic ingredient of oil. ". Anyway, on March 25, 717, Leo the Isaurian, the head (or commander-in-chief) of the main forces in Asia Minor, seized the throne, and the situation became so critical that the Arabs took the opportunity to lay siege to Constantinople both by land and by sea, since there were still gaps, at least on the borders of Toros. As for the Balkans, all that remained of the Empire's sphere of influence was its narrow slice of the Aegean coast.
As the saying goes, a lean camel is bigger than a horse. Thanks to the political reorganization that began in the last century, and the quality of the warriors who defended their country at every step, the empire finally withstood the Arab invasion. From the end of the 8th century onwards, the Empire accelerated the recovery of the Slav-occupied territories of Troas, Chalcidic, central Greece and the Peloponnese. from the middle of the 9th century onwards, the Arabs were no longer able to cross the Toros Mountains. Instead, Byzantium renewed its conquest of the Armenian frontier in the north.
Custodian Justinian issues a code of laws