A Byzantine timeline created by Basileus Giorgios. Currently has two versions: This original, older one, and a reboot/rewrite, version 2.0, available further down the page. Both versions have very handy chapter guides, so don't be afraid to use them.
The point of divergence starts in the reign of Emperor Isaac I Comnenus. Here, Isaac lives longer and is able to bequeath his Empire directly to Alexius I. From this point, this comprehensive and well written TL follows the fortunes of a Roman Empire that never suffered the terrible disaster of OTL's Manzikert all the way up to the use of steam power and industrialisation.
Part I- The Komnenoi 1057-1212
Chapter 1: Isaac's Empire (1057-1075)
Chapter 2: The Return to Italy (1075-1118)
Chapter 3: The Scholar Emperor (1118-1143)
Chapter 4: Wider And Wider (1143-1153)
Chapter 5: The Church Reunited (1153-1180)
Chapter 6: The Last Komnenids (1180-1212)
Part II- The Rossinoi 1212-1306
Chapter 7: The Gathering Storm (1212-1227)
Chapter 8: George The Great (1227-1234)
Chapter 9: Demons And Demokratia (1234-1269)
Chapter 10: The Second Invasion (1269-1273)
Chapter 11: The Great Khan Humiliated (1273)
Chapter 12: Constantine X: (1273-1306)
Part III- All The Pope's Men 1306-1356
Chapter 13: Samuel's Rise: (1306-1328)
Chapter 14: The Empire Crumbles: (1328-1334)
Chapter 15: A Flash Of Hope: (1334-1340)
Chapter 16: North Johannia: (1340-1342)
Chapter 17: Samuel's Fall: (1342-1356)
Part IV- The Early Syrians 1356-1477
Chapter 18: The Empire Restored: (1356-1369)
Chapter 19: Rebuilding The Church: (1369-1380)
Chapter 20: Prelude To Colonialism: (1380-1402)
Chapter 21: Leo and Theophilius: (1402-1423)
Chapter 22: The Last Great Uprising: (1423-1436)
Chapter 23: Annihilating Distance: (1436-1477)
Part V- On Top Of The World 1477-1564
Chapter 24: The Clashings Of Civilisations: (1477-1488)
Chapter 25: Romanus The Good: (1488-1518)
Chapter 26: One Woman To Rule The World: (1518-1527)
Chapter 27: Anna's Men: (1527-1540)
Chapter 28: The Golden Age: (1540-1564)
Part VI- The Empire Challenged 1564-1633
Chapter 29: Unfettered Demokratia: (1564-1572)
Chapter 30: The Dawn of Modernity: (1572-1593)
Chapter 31: The Partition of India: (1593-1602)
Chapter 32: Horeiarios, Doukas, and Miroyan: (1602-1609)
Chapter 33: Thanjavur: (1609-1615)
Chapter 34: Armenia Aflame: (1615-1623)
Chapter 35: General Efthisiou: (1623-1633)
Part VII- Hurtling to Ankyra 1633-1684
Chapter 36: The Cape War: (1633-1644)
Chapter 37: Portugal's Oil: (1643-1655)
Chapter 38: A Church of the Body and the Blood: (1655-1673)
Chapter 39: David III: (1643-1653)
Chapter 40: The Fall of the Roman Empire: (1653-1665)
11th Century The century starts off well for the Romans, as they reach new heights of power and influence under Basil II. However, this is quickly followed by a steady decline over a thirty year period. Fortunately, this does little lasting damage to the Empire, and the soldier-Emperor Isaac I Komnenos is able to restore order over an eighteen year reign, despite the rising Turkish threat, which is neutralised after the indecisive Battle of Manzikert. After a long war, the Normans are finally expelled from South Italy, and Sicily, Corsica, and Sardinia are reconquered.
12th Century The century is dominated by Roman expansion. Roman armies reconquer much of Italy after crushing the Germans in alliance with the Papacy. The Church is briefly reunited, before permanently dividing again, into a roughly Catholic north and west, based in Paris, and a “Uniate” south and east based in Rome and Constantinople. Romans annex Armenia, Hungary, Syria and Palestine, but are left severely stretched by the death of Manuel I, whose achievements are largely negated by his son Alexander IV. In Western Europe, the Holy German Empire (which has lost the title “Roman”) is expanding in France and the Baltic, as are the English.
13th Century The last Komnenid Emperors are expelled by George Rossi, an Italian soldier who declares himself George I. The themata, ruined by thirty years of neglect under the later Komnenoi, are largely abandoned, and old classical style professional armies are raised. The Mongols attack the Romans on two occasions, but are repulsed both times, despite causing major damages to the Roman sphere of influence in the second invasion of 1272. A semi-democratic form of government starts to emerge. Romans regain Mongol devastated Egypt, and forge closer ties with Russia. In Britain, Norman power begins to decline.
14th Century The Empire experiences 50 years of chaos between 1306 and 1356, due largely to the machinations of Pope Samuel II. The East is devastated by attacks from the rump-Mongol Khanate, based in Persia. Order is eventually restored by Isaac of Syria, who murders Pope Samuel personally before defeating the Persians and reforming the Church. Technological advancements in the second half of the century begin the Industrial Revolution. Germans invade Norway, forcing the Norse west, where they discover the New World and found Jensby. Britain collapses into anarchy. Spain leaves the Uniate Church.
15th Century The Syrian Dynasty continues capable and competent rule, expanding out into the Red Sea. The Senate begins to emerge as a significant political force in its own right. A violent workers' revolt is crushed, but concessions are made. Railways introduced from 1453 onwards. Romans establish dominance over the Indian Ocean and colonise Medruthis and Taprobane. Mongol Empire of Persia begins to decline, but English power in Britain is restored, leading to the founding of New York upon the Amazon, and the British Empire. Spain, Portugal, Germany and Jensby vie for influence in the New World, as the natives are crippled by plague. Contact made between Constantinople and Ming China.
16th Century Further Roman expansion in the Indian Ocean and smaller surrounding seas leads to the collapse of the Persian Khanate. Anna I becomes the first Roman Empress to legally inherit the throne in five centuries, but her heir appears to be a Russian, causing wariness in Constantinople. Native Johannians recover their strength, and begin to build kingdoms and empires with Old World technology, blocking further European expansion. The Syrian dynasty is exhausted, and replaced with a Russian dynasty headed by John V, which immediately runs into trouble attacking democratic Muslim states in the Persian Gulf. By the end of the century however, the situation has stabilised, and the Romans begin a cold war with the revived Persians over the rubble of what remains of the great empires of India.
17th Century The Romanov Dynasty continues to rule the Roman Empire, but its grip on power begins to slide alarmingly, allowing the Senate to increase its political roll. The office of Grand Logothete becomes more and more important under the Armenian Christopher Miroyan and his successors. At the Battle of Thanjavur, the Emperor George III becomes the last Roman Emperor to win a battle in his own right. The Xenonic Dromon, the world's first flying machine, is invented. In the West, the European monarchies come of age, with power being shared between Britain, Germany and Portugal, supplemented by Spain and the United Kingdom of Navarre and Occitania. The Tongvan Tribe adopt a bloodythirstly cannibalistic heresy known as “The Church of the Body and the Blood”.
A re-write of the original story. The world of IE 2.0 will develop in more of less the same way to the original, but there'll be a lot more detail, and twists and turns along the way.
Part I- The Komnenoi 1057-1212
The Roman Empire in 1057 (by Ares96)
Chapter 1: The Pretender (1057-1063)
In which Isaac Komnenos takes the throne, the Petchenegs cause trouble, and the Anatolian aristocracy goes out on manoeuvres.
Chapter 2: Taming the Beast (1063-1075)
In which Isaac's troubles come to a head at Claudiopolis in Bithynia, Michael Psellos and the Doukai consolidate themselves, and the Normans and Turks continue to prove a nuisance.
Chapter 3: Education for an Emperor (1075-1082)
Psellos and Alexios are drawn more and more to the West, and the Norman threat becomes even more formidable.
Chapter 4: Heart and Soul (1082-1092)
The tide begins to turn in the Empire's favour in Italy, but back in Constantinople, the Imperial family are beginning to turn on one another.
Chapter 5: The Weight of Empire (1082-1100)
Empires clash - and personal tragedy looms.
Chapter 6: The Triumph of Alexios Komnenos (1100-1117)
Courtiers and generals plot and manoeuvre for advantage, as Alexios heads East to consolidate his authority. Meanwhile, a new alliance is formed in the City.
The Turkish Successor States, circa 1111 (by Ares96)
Chapter 7: The Dragon Emperor (1117-1122)
Isaac Komnenos the Younger finally gains the throne, but the House of Komnenos itself seems ready to split apart. Jordan discovers his true potential and Basilios attempts to save the peasantry.
Chapter 8: Pinnacle (1122-1152)
Isaac's son Manuel becomes Emperor, and the House of Komnenos reaches the height of its power, epitomised by the birth of the Uniate Church.
Appendix A: A Brief History of the Anglo-Norman Kingdom 1066-1149.
Chapter 9: Out with the Old (1152-1156) Manuel is succeeded by his son John II, who is immediately forced to confront the loss of the great eunuch diplomat Basilios. Out in the provinces, Jordan of Aversa finds himself under threat from new foes, both within the Empire and without.
Chapter 10: The Ladies' War (1156-1162)
The death of the Emperor John's father-in-law, Andrew II of Hungary, opens up new opportunities on the Empire's northern frontier. Meanwhile, the Empress Theodora unexpectedly delivers a son, named Alexander.
Appendix B: A Brief History of the Anglo-Norman Kingdom 1142-1190.
Chapter 11: Sultan and Emperor (1162-1180)
A small civil war amongst the Turkish Salghurids leads to the rise of Kurboga of Egypt, a formidable new foe for the Empire. Accompanied by the young generals David Bringas and ibn Yusuf, John goes to war, but with heavy consequences.
Chapter 12: Filling the Vacuum (1180-1185)
The death of John II is marked by constant struggles for power in Constantinople between his inadequate successors, while on the fringes, ambitious generals plot to replace the Komnenoi with their own dynasties.
Chapter 13: Eirene Nafpliotissa (1185-1187)
In the aftermath of Eirene Nafpliotissa's emergence as Augusta new conflicts burst into life, as her enemies within the Empire and without test the power of a so-far untested Empress.
Chapter 14: The Favour of our God (1187-1212)
The Empress Eirene has consolidated her power and defeated all of her internal enemies, but resentment remains, with the Empire determined to rid itself of her. As the Empire begins to collapse inward, an old general finally begins a revolt that will have far-reaching consequences.
Chapter 15: The Calm Between Storms (1212-1229)
Within Eirene and the Komnenid dynasty deposed, a new Emperor, George the Italian, rules in Constantinople, and begins to put right the errors of the past reign. Rhomania enjoys peace and prosperity, and a cast of new characters emerge to bring in the thirteenth century.
Chapter 16: The Khan and the Queen (1221-1229)
To the East of the Empire, a civil war in Seljuk Iran lets in a terrifying new threat from the distant East: the savage, sky-worshipping Jurchens.
Chapter 17: Flame and Saltwater (1229-1232)
Years of Roman, Turkish and now Jurchen squabbling over Armenia result in a savage Jurchen invasion of the Empire. As city after city falls to the hordes from the East, George the Italian is forced to watch his achievements crumble, and a terrifying new foe reach the very gates of Constantinople.
Chapter 18: The Search for Stability (1232-1246)
As Emperors rise and fall, the Empire adapts itself to a new existence as a drastically shrunken power - but an unexpected saviour is waiting in the wings.
Chapter 19: Demetrios the Regent (1246-1274)
Supported by the Jurchens, the lowborn Demetrios takes power as Regent over the child-Emperor Constantine X, and initiates a series of reforms that prepare the Empire to face the future. Elsewhere, however, Jurchen power only continues to grow.
Chapter 20: Ākǔttǎ Khan (1274-1281)
A glorious new leader emerges within the Jurchen Khanate, and a centuries-old dynasty finally collapses.
Chapter 21: The Storm Breaks (1281)
The Empire faces its most dangerous threat in centuries as two vast Jurchen armies converge on a Constantinople riven by weakness and factionalism, its armies scattered and beaten. Only God can save the Roman people now.
The timeline has won the “Best Continuing Medieval Period Timeline” category in the 2011 Turtledove Awards.