|Official Languages||Greek, Latin|
|First Ruler||Constantine I|
|Last Ruler||Constans Augustus II|
The Eastern Roman Empire, called the Byzantine Empire by modern scholars. In this timeline, the Byzantine Empire defeated the forces of Islam at the Battle of Yarmuk and preserved its empire. It is then able to extend its power throughout the Mediterranean world, establishing itself as a colonial power and remaining a strong nation state in more modern times.
Victory at Yarmuk
The Battle of Yarmuk was undeniably the victory that the failing powers of Byzantium had been looking for; it gave them the respite needed to make an attempt to reconsolidate their hold on some of the more peripheral provinces. This they managed in much of Southern Italy, though the North was lost to the Lombard League. More importantly, it allowed the Emperor to reinstitute his control over the Papacy, thus eliminating the impending schism. Moreover, the Arabs served to destroy Byzantium's main rival Persia, which allowed Byzantium to establish stronger trading influences with the East (namely the Khazar Khanate).
Wars against the Arabs
Except for a short, provincially scaled and ultimately unsuccessful conflict with the Berber Kingdom of Mauretania, no fighting was sustained by the Byzantine army for another generation. However, all of this time, the Arabs were moving. The Byzantines initial rivals, the Rashidun had been overthrown and replaced by supporters of Uthman, a powerful merchant prince, who went on to found the Ummayad Dynasty. The Byzantines took little notice of this change; they felt they had nothing to fear from financially minded Uthman. This indeed turned out to be the truth - Uthman was assassinated in 653. However, in his heir Al Wahdiq they found their match. Though a failed administrator, Al Wahdiq knew how to deal with his many enemies: he destroyed the Kushans in 666. The Byzantines were drawn into Al Wahdiq's invasion scheme when he invaded the territory of their Khazar allies in 668, though they failed to act on it until 670, by which point Merv had already been annexed by the Ummayads. Byzantine intervention certainly took the pressure off the Khazars, but for the Byzantines, it was a tough trial. The Ummayads were very different to the Rashidun - and Al Wahdiq proved himself to be an outstanding commander. However, the sack of Mecca in 673 and the siege of Antioch in 674 put an end to this conflict. Outstanding or not, Al Wahdiq proved the true strength of the Byzantine Empire. It was certainly superior to that of Islam. Peace was concluded at Antioch, following a quick conflict between the Arabs and the Khazars that proved to be the end of the latter. Byzantium was certainly capable of defending herself, but protecting the interests of her allies was evidently an entirely different matter.
The Struggle for Italy
A generation had passed before the next military challenge came to the Byzantine state, during which time there was a little internal upheaval within the Heraclian dynasty. Overall, however, this did not overly affect the empire as a whole - despite the continual interruption of military advances. However, Leontios, the Emperor that succeeded the last genuine Heraclian candidate, was presently (698AD) called to Italy by the Byzantine proconsul of Rome, who had fled to Naples following a rebellion by the Pope, who was supported in his actions by the Lombard Dukes of Salerno and Benevento, who between ruled much of central Italy. This they had done as semi-independent vassals of the Byzantines for about 100 years, but due to the stories of troubles in the East reaching their courts, they thought it appropriate to exploit Byzantium's supposed weaknesses.
They were entirely mistaken. Leontios immediately set out for Italy, accompanied by an army raised in the Balkans specially for the occasion. Papal arrogance proved enough to stir the hearts of the Lombard dukes, who called on their northern kinsmen for aid. But the Lombard league simply weren't interested; they felt it lucky that they had sustained their hold on Cisalpine Italy for so long - and did not want to be drawing attention to themselves. It took two sharp defeats by Leontios to break the forces of Salerno and Benevento, who consequently fled northwards, causing havoc as they went. Justinian continued on his march to Rome, which fell without a fight. During the legal exchange that followed, the Pope and all 12 of his cardinals in Rome were arrested and sent back to Constantinople in chains. Leontios then considered moving the Papal office to reside in his sight in Constantinople, but was persuaded otherwise by representatives from both the Frankish and Visigothic royal houses, both of whom had strong objections to Leontios' plan. Moreover, the dispute was one of the reasons which lead to a military coup in Constantinople by Tiberius, who successfully overthrew Leontios at the close of the year. In order to pacify the situation (both the Franks and the Visigoths threatened to leave the Catholic Church if a compromise was not reached) and consolidate his position as Emperor, Tiberius conceded over the issue. He even allowed the Franks and the Visigoths to provide bishops to reform the College of Cardinals, in order to conciliate the Western nations as allies of Byzantium.
The Danube Bulgar Khanate
In 620 AD, the Khazar Khanate destroyed the Khanate of Great Bulgaria, leaving only the lands around the Danube estuary in the form of the ancient Hunnic race. Though, due to the events predating the fall of Rome, the Byzantines had little time for the Huns (now called the Bulgars), they appreciated that to invade the wilderness of the Danube valley would be more trouble than it was worth - and that rather than wasting the men and resources of the creaking Byzantine state, they could establish a protectorate over the wild horsemen of the Danube valley. The Bulgars saw no problems with this; what was left of their former prestige had been destroyed by the Khazars in 620, and through vassalage to Byzantium, they could only gain from Byzantine subsidies. Slowly but surely, relations between the nations grew; by the late 7th century, the Byzantines had less concern for their Northern borders than ever before - and the only other threat - the Khazar Khanate - had been neutralised by the Arabs of the Ummayad Caliphate.
This peaceful relationship was rocked in 695 AD by the arrival of the Patzinaks, who crushed the armies of the Bulgar Khan. The Byzantines, who had promised reinforcements, failed to provide a necessary force - and it didn't take long for the Patzinaks to subjugate the entire Danube estuary. The Bulgars were understandably unhappy with the Byzantines, to whom they sent many pleading envoys begging for aid. But the Byzantines, though distressed by the news, were unwilling to attack an army as great as the Patzinak horde; consequently the Bulgar Khan changed his tune. By becoming a vassal of the Patzinaks, he obtained their permission to raid Byzantine lands. The Byzantines reacted with vigour at Sirmium; subsequent raids by the Bulgars were too insignificant to be of any importance to Constantinople.
However, in 702 AD, it was the Byzantines' turn to change their tune. The Khan of the Danube Bulgars had died and been replaced by his fiery son, who was keen to relinquish Patzinak vassalage. At the same time, however, he also tried not to involve the Byzantines, but this couldn't be avoided forever. Envoys from Emperor Justinian II were sent to the Khan's court to talk to the new Khan, who had come to the realisation that he couldn't make his dream effective without Byzantine aid. However, the Byzantine army was too slow to take up the call to arms, by the time they reached Bulgar territory, the Bulgar army had already been wiped out by the Patzinaks. The young Khan had been captured and executed at the hands of Patzinak warlord Tughril Alp Qinsai, who then went on to defeat the Byzantine force and invade the Byzantine province south of the Danube. Justinian II rapidly collected together an army from Constantinople, Salonika and Rhodes - and in a carefully planned ambush outside Kios, he annihilated the Patzinak army, sending the prisoners back to the Patzinak capital at Tana as a sign of peace, Begrudgingly, the Patzinak council accepted peace on this basis, but peace was uneasy. Byzantium and the Patzinak Empire seemed on the brink of war.