I wrote a 50 year timeline for after a reversed Manzikert. By 1125:
-Romanus IV keeps the throne, marries a Bulgar woman to instill loyalty among those people
-Eventual reconquest of Syria, Levant, Jerusalem, southern Italy, Sicily, Wallachia, Sardinia, Corsica, Caucasus region, SE Spain, colonize much of southern Ukraine after alliance w/ Rus as buffer to northern barbarians. -Byzantine Protectorates over Moldavia, modern Jesidian, east-central Italy, Venice, Tunis/Carthage, Kiev Rus
-Scattered Byzantine colonies throughtout world
-Greeks launch expeditions into Atlantic Ocean (one lands in Canaries, another in the Azores, a few chart eastern Atlantic ocean the is lost after catching ocean currents to modern Brazil near Recife where crew builds new town)
-Byzantines back Persian revolution from Kaliphate, uneasy truce between them
-Normans take Corfu and try to land in Greece, fail, attract Byzantine invasion later on
-Byzantines like Chinese idea of a civil service complete w/ exams and wooden printing press, they decide to use metal type instead
-gunpowder brought over early, used for fireworks initially
-mild Renaissance begins early as cultural exchanges between Byzantines and Arabs accelerate with some Chinese tech/ideas added in
-More unified HRE in face of Byzantine borders and allied-then-crushed Northern Italy
-France, England, Castile, Aragon begin forming defensive alliance to tsay out of Muslim, HRE, and Byzantine hands
-Byzantine engineers study and eventually start rebuilding (small) aqueducts, sewer systems, and Roman-style roads with curves
-Seven Imperial Libraries, designed to store knowledge as the Great
Library did