Constantine V conquers Bulgaria?

[Vinization]

Constantine V was one of, if not the, best emperor of the Byzantine Isaurian dynasty. He was a competent administratior and, most famously, launched several campaigns against the Bulgars, but despite scoring many victories (and some defeats) and their turmoil, he failed to subjugate them.

What if he defeated them and pushed the empire's border back to the Danube, roughly giving it the borders left by Basil II three centuries later, with the added bonus of Sardinia, Corsica and maybe Venice? Let's say he does it in the 750s (a victory at Rishki Pass?) so he still has some years left to live (he died in 775). What would be his next move? Would he march against the Lombards in an attempt to reverse Constantinople's declining fortunes in Italy (perhaps by recapturing Ravenna?), or would he march against the Arabs like he did before his Bulgarian campaigns, taking advantage of the Abbasid Caliphate's momentary instability? I would put my money on the latter, but you never know.

Also, Leo IV would probably live longer due to butterflies (he died from tuberculosis at the age of 30), which would nip Irene's reign in the bud. Would the Carolingian Empire not exist?

Most importantly, would Iconoclasm prevail in the long run? The Isaurians were iconoclasts, and such a great victory would only embolden them and show the empire that they were favored by God.

 

[Teutonic_Thrash]

How timely, for I've just wrote an Isaurian conquest of the Bulgars for my timeline. Admittedly it's not by Constantine V but by an alternate grandson also called Constantine VI. In my timeline, Leo IV dies in 779 while facing an Abbasid invasion. His brother Nikephoros is enthroned instead of his son Constantine, and Nikephoros goes on to defeat Krum which leads to the splitting of the Bulgar empire. The eastern half of the Bulgars engage in violent persecution of Christians, which leads to a Roman invasion under Nikephoros' son Constantine VI. The eastern Bulgars are conquered about 828.
The Isaurians still support Iconoclasm but in order to shore up control over the "Papacy" and Byzantine territories in Italy, an alternate Second Council of Nicaea results in a compromise solution where enforcement of Iconoclasm is devolved to bishops over their respective sees.

 

[Vinization]

How timely, for I've just wrote an Isaurian conquest of the Bulgars for my timeline. Admittedly it's not by Constantine V but by an alternate grandson also called Constantine VI. In my timeline, Leo IV dies in 779 while facing an Abbasid invasion. His brother Nikephoros is enthroned instead of his son Constantine, and Nikephoros goes on to defeat Krum which leads to the splitting of the Bulgar empire. The eastern half of the Bulgars engage in violent persecution of Christians, which leads to a Roman invasion under Nikephoros' son Constantine VI. The eastern Bulgars are conquered about 828.
The Isaurians still support Iconoclasm but in order to shore up control over the "Papacy" and Byzantine territories in Italy, an alternate Second Council of Nicaea results in a compromise solution where enforcement of Iconoclasm is devolved to bishops over their respective sees.

Krum of all people being defeated? Would've been easier to just buttefly the guy away, considering how much of a genius he was. Does Nikephoros turn his skull into a drinking cup, for extra irony?

 

[Silver01]

its not imposible as in 756 bulgaria had collapsed in to civil war due to the collapse of the dulos clan , constantine could do it , this causes some effects like the earlier chirstianization of bulgaria , in terms of what comes next well the empire has reastablished the danube as border so it would be done with it , the empire migth join the franks in to attacking the avars khagante making vassals north of the danube to secure peace and a buffer zone.
how ever this frankish roman alliaince would not last as conflict over italy would rise , aistulf achieved some notable successes conquering ravena in 751 by assuming bulgaria was conquered in 760 and the avar one in 760s the mid 760s would be the franks and romans ganing up on the lombards and figthing eachother i say the compromise would be that the romans get souther italy and the franks get the north while papal states are granted "freedom" and council is held on icononislam with really getting no where , harrun al rashid great raid migth not happend or not punch as deep as their would be no iriene who killed competent generals who opposed her .but due to war with the franks harrun could make some attacks this migth hurt the isuarians legitemicy and migth cause some rounds of iconoclasam which migth tip the scales in favor of the non icnoclast views ,so when al rashid dies and the civil wars beging the empire wont have to deal with krum and just italy . the invasions of 820 could be butterflied away but when the abbasid caliphate declines and with no bulgarian front the byzantine recovery migth be greater as they could sent their full force to the east conquering more of the levant and syria.

 

[Teutonic_Thrash]

Krum of all people being defeated? Would've been easier to just buttefly the guy away, considering how much of a genius he was. Does Nikephoros turn his skull into a drinking cup, for extra irony?

Krum continually defeated Nikephoros on the field, so the latter devised a naval invasion of Odessos/Varna while Krum was busy besieging in the south. After the conquest of Odessos, the Byzantines moved on to successfully besiege Pliska and then defeated the demoralised Bulgar army in battle (where Krum died).

 

[Vinization]

Alright, I'm having a bit of a brain wave so I'll just throw in some of the potential consequences of the POD shown in the opening post.

1. An entire series of horrible defeats (Pliska, Anchialus, Gates of Trajan) is butterflied away.
2. The empire has its western border secured centuries earlier.
3. The Abbasids aren't completely stable yet, facing two Alid revolts in 762-63 and in 786. There was also a Coptic revolt in 767. Could Constantine or Leo IV take advantage of this instability and invade/ conquer Antioch and Aleppo?
4. How would an Iconoclastic dynasty handle Muslim subjects within its borders?
5. The pope would have to play the Franks and Byzantines against each other while also handling the Lombards, who would probably be taken care of by both of them.

EDIT: The empire, if competently led (usurpers are a constant issue whenever anything remotely Roman is involved), would also be in a much better position to take advantage of the Anarchy at Samarra and the Zanj Rebellion.

 

[Tyler96]

The important question is whether a more successful Constantine V gets a... less unfortunate epithet.

 

[Lascaris]

The important question is whether a more successful Constantine V gets a... less unfortunate epithet.

Likely not. Poor man was arguably one the best emperors ever to wear the purple... but he offended the sensibilities of the monks. Who ever heard they should had been treated like normal citizens and not let to skin the masses. Unacceptable!

 

[Vinization]

The important question is whether a more successful Constantine V gets a... less unfortunate epithet.

Maybe he will. Iconoclasm will likely last longer, if not win the dispute, thanks to his glorious victory. Iconophile historians will still hate his guts, but we'll probably have more (surviving) historians on the other side praising him too.

 

[Vinization]

Calling in some of this site's more prominent Byzantinophiles/people who wrote or are writing TLs focused on them. Their input could help with this discussion.

@Basileus444 @Basileus Giorgios @wcv215 @Sargon

 

[Xenophonte]

in terms of what comes next well the empire has reastablished the danube as border so it would be done with it , the empire migth join the franks in to attacking the avars khagante making vassals north of the danube to secure peace and a buffer zone.

Wouldn't be more probably that for achieve this goal that the Bizantines would support/allied with the Avars against the Franks?

 

[Silver01]

Wouldn't be more probably that the Bizantines would support/allied with the Avars against the Francs?

not quite the avara khagante was dying by to keep it alive would have been to much also the distance would mean that the franks still take their chunk of of them also like i said its much better that he did something like krum and let charlegamane have its share and he took his , since like i said one can prop up many tribes to be vassals to add a buffer zone