POD - Early Middle Ages (7th Century - 10th Century)Edit
The backstory starts with a fairly simple POD.
The POD begins when the Byzantine Emperor, Mauritius, isn't killed in the year 602, when he decides to call back the military Winter quarters in the Danube, this avoids the mutiny that sparked within the military.
Hence this, his reign lasts another five years, with him dying in 607 Attero Domini and keeping a more stable nation for a while, Khusrau II doesn't have a reason to launch an early attack on the Romana Imperium, thus preventing Persia from getting any gain from the Byzantine Empire and thus avoiding the military exhaust that allowed the Muslims to expand as quickly as they did.
Maritius' son, Theodosius, is proclaimed Emperor, however his ruling means a certain success for the Empire's, enemies as his loses Italy and faces trouble in North Africa as many Berbers attempt to gain control of the Exarchate of Carthage. The Persians attack the Levant and Egypt in 615 CE. However, their attempt fails, as the Byzantine army is not focused on a internal crisis like in OTL, instead they have both the strength and the force to push the Persians back to the east.
Era of Islam: Failure and SuccessEdit
The Byzantine Empire stands strong by the time Islam arrives upon the Horizon of the Middle East. Persia however isn't that strong, after the defeat of Khosrau's army by the Byzantines, the Persian nobles rise against the Shah forcing him to flee, in the midst of the civil war, Persia loses its land in Arabia and south of the Tigris and Euphrates.By 635 the Caliphate dominated most of Arabia and everything south of the Tigris and Euphrates from Persia. Caliphatei had gained enough power within Arabia as to concern into expanding the Caliphate beyond their current domains. Eventually they sought to expand west. although the Arab army was recent and not as trained as the Roman the Arabs successfully took over the Levant in matter of a weeks, the byzantine emperor Theodosius sent a elder General, known for its success against the Persians during the ephemeral Roman-Persian war, Heraclius the young, son of the Exarch of Africa, the Byzantines defeated the Arabs in the Battle of Yarmouk (succeeding due to the fact that the army was more prepared and less exhausted). The Arabs are, as a result, expelled back from whence they came. However the Caliph, Umar ibn Al-Khattāb, saw the defeat as a mistake that wouldn't repeat itself again, he continues launching attacks instead to Persia and Ethiopia, nations which had faced recently crisis and civil wars and that were in different state than the Roman empire.
However they have little to no success, their only achievement is to push for a strengthening of the Ethiopian army and bringing Persia to some forceful peace to avoid the empire falling at hands of the Muslims (which most of the Zoroastrian nobles want to avoid. The Arabs focus into spreading Islam peacefully gaining allies with some Nilotic tribes and Cushtic peoples in Somalia.
The Roman empire faces a big dilemma in Italy and Spain. In Spain the Visigoths attempt with some success in taking over the Province of Spania while in Italy the Lombards have managed to take over Ravenna and most of the Exarchate but Rome itself, heavily protected by the emperor Theodosius III, by 642 when Theodosius III dies the only held territories in peninsular Italy is southern Italy and Rome. However in Spain the situation is different, Heraclius, prior to the death of Theodosius, led a campaign to recover and secure the province of Spania and Mauretania tingitania, he is successfully gaining even some of the lost land back to the empire by 639. In the West the Franks Remain divided only until 612 when Austrasia and Orleans unite, leaving Neustria and its northern holdings as the sole independent Frankish territory. However, this state is soon finished as Neustria and Austrasia Unify in 614 unify, Forming the Kingdom of the Franks (Regnum Francorum), the Kingdom, unified by Chlothar II didn't took too long to fall as it only lasted two decades.
After this Neustria sought room to expand turning their eyes towards Britannia, the long forgotten islands far from the messy continental situation and a weak set of kingdoms across the sea. the conquest of Kent started in 639 after a small fleet of ship crossed and landed in the south, it didn't took to long for it to fall after the battle of Dubrae where the Neustrians successfully defeated the army of Kent. in less than a year the had conquered Kent, Sussex and Essex. After that Neustria became a powerful trading nation between the isles and the continent. An exchange of peoples from northern France and Britain occurred. this also brought a romance language still strongly close to Latin back to Britain. In France the situation remains tense as Aquitania, Neustria and Austrasia have become belligerents with each other, creating an atmosphere that would delay for some time the unification of France.
In Italy the Lombards have taken and Unified most of Italy after defeating the Byzantines in 640, and conquering Benevento and Spoleto, The only territories they haven't gained are Rome, Naples and southern Italy still loyal to the Byzantine monarchy and still heavily loyal to the idea of a Roman empire. The rest of Italy is subjugated by the Lombards.
In central Europe the Avars move towards Germany trying to conquer Bavaria and some of the central German tribes that had remained independent off the Austrasian domination. after they failure the Avars focus on conquering the Slavic tribes in eastern Europe where they do have a certain success reaching the Baltic sea.
The 7th Century ends with the Muslim advance into Persia being finished and the Byzantine empire retaking southern Spain and Northern Mauritania back to the Roman empire. Persia losing most of the crescent fertile and France being divided into three while England is being unified by the Neustrians who around 680 conquered Anglia and Wessex the Avars lose most of Ukraine to the Khazars who appear more friendly towards the Byzantines.
East Asia: Rise of the SunEdit
In the East the Chinese Sui dynasty is soon dethroned by the tang who expand their empire taking advantage of their neighbour's weakness. Silla allied itself with the Tang Dynasty, subjugating Baekje and defeating Goguryeo to unite the Korean Peninsula under one ruler.