The Byzantine Empire (or Byzantium) endured from 324–1453. It was the Greek-speaking Eastern Roman Empire, ruled by emperors in direct succession to the ancient Roman emperors and began with the foundation of Constantinople by the emperor Constantine I in 324. Distinction between "Roman Empire" and "Byzantine Empire" is purely a modern convention, it is not possible to assign a date of separation. Byzantium was called the Roman Empire and also Romania (Greek: Ῥωμανία, Rhōmanía) by its inhabitants and neighbours. It ended with the conquest of Constantinople by the Ottoman Turks on 29 May 1453. Between those dates are many important events, undoubtedly more than can be fit into this chronology. Attempts at periodization are interpretative, the simplest being three basic phases:

Early (324–ca. 650), Middle (ca. 650–1071), and Late (1071–1453). For 1071, the date of the battle of Mantzikert, some might substitute 1204, the year the Fourth Crusade conquered Constantinople. In any case these phases are conventional ones.

324–337 Reign of Constantine I as sole ruler
324 Foundation of Constantinople
325 First Ecumenical Council (at Nicaea)
330 Dedication of Constantinople
337–361 Reign of Constantius II, with Constantine II (337–340) and Constans (337–350) as augusti.
ca. 343 Council of Serdica
353 Defeat of Magnentius
359 Persians capture Amida
361–363 Reign of Julian
363–364 Reign of Jovian
364–378 Reign of Valens, with western emperors Valentinian I (364–375) and Gratian (375–383)
376 Visigoths cross the Danube
378 Battle of Adrianople
379–395 Reign of Theodosius I, with western emperor Valentinian II (ruled with Gratian 375–383; sole western emperor 383–392)
381 Second Ecumenical Council at Constantinople
391 New laws prohibit the offering of pagan sacrifices; all temples ordered closed
395–408 Reigns of Arkadios in the East, with western emperor Honorius in the West (reigned 395–423)
400 Massacre of Goths in Constantinople
402 Honorius’s court retreats from Milan to Ravenna
408– 450 Reign of Theodosios II in the East, with western emperor Honorius (until 423) and Valentinian III (reigned 425–455)
410 Rome sacked by the Visigoths
413 Theodosian land walls completed at Constantinople
425 University of Constantinople reorganized
429 Vandals and Alans cross over to North Africa
431 Third Ecumenical Council at Ephesus
438 Codex Theodosianus issued
439 Vandals capture Carthage
449 “Robber Council” at Ephesus
450–457 Reign of Marcian
451 Fourth Ecumenical Council at Chalcedon
453 Death of Attila
455 Rome sacked by the Vandals
457–474 Reign of Leo I
468 Naval expedition against the Vandals fails
474 Reign of Leo II, with Zeno as co-emperor
474–491 Reign of Zeno
475–476 Basiliskos usurps power
476 Western emperor Romulus Augustulus overthrown by Odoacer
482 Henotikon issued
484–519 Akakian Schism
491–518 Reign of Anastasios I
497 Isaurian revolt quelled; Theodoric ruler of Italy
505–507 War with Persia
513–515 Revolt of Vitalian
518–527 Reign of Justin I
527–565 Reign of Justinian I
529 Justinian closes the Academy in Athens
532 Nika Revolt
532–540 Peace with Persia
533–534 Vandalic War
534 Corpus Juris Civilis issued
535–554 Ostrogothic War
537 Hagia Sophia dedicated
540–545 War with Persia
545–550 Five-year truce with Persia (renewed 551, 556)
ca. 550 Southeast Spain occupied by Byzantine forces
553 Fifth Ecumenical Council at Constantinople
562–572 Peace treaty with Persia
565–578 Reign of Justin II, with Tiberios as caesar (574–578)
568 Lombards invade Italy
572–591 War with Persia
578–582 Reign of Tiberios I
ca. 578–585 Slavs settle in Greece in great numbers
582–602 Reign of Maurice
586 First siege of Thessalonike by Avars and Slavs
602–610 Reign of Phokas
603 War with Persia resumes (to 628)
610–641 Reign of Herakleios
611–622 Persian attacks on Asia Minor
626 Avars and Persians besiege Constantinople
630 Byzantine victory over Persia
632 Death of Muhammad
635 Arabs conquer Damascus
636 Battle of the Yarmuk River
638 Arabs conquer Jerusalem; Ekthesis issued
641 Reign of Herakleios Constantine and Heraklonas
641 Reign of Heraklonas, with Martina as regent
641–668 Reign of Constans II
642 Arabs conquer Alexandria
646 First Arab raids into Asia Minor
647 First Arab attack on Cyprus
648 Typos of Constans II issued
656–661 Civil war in Caliphate
658 Slavs from sklavinia resettled in Asia Minor
663–668 Constans II in Italy and Sicily
663–678 Annual Arab raids into Asia Minor
668–685 Reign of Constantine IV
674–678 First Arab siege of Constantinople
680–681 Sixth Ecumenical Council at Constantinople
681 First Bulgarian Empire established
685–695 Reign of Justinian II
695–698 Reign of Leontios
698 Arabs capture Carthage
698–705 Reign of Tiberios II
705–711 Reign of Justinian II (again)
711–713 Reign of Philippikos
713–715 Reign of Anastasios II
715–717 Reign of Theodosios III
717–741 Reign of Leo III
717–718 Arab siege of Constantinople
730 Leo III bans all religious images
740 Battle of Akroinon
741–775 Reign of Constantine V
742–743 Revolt of Artabasdos
751 Lombards capture Ravenna
754 Iconoclastic Council of Hiera
775–780 Reign of Leo IV
780–797 Reign of Constantine VI
787 Seventh Ecumenical Council at Nicaea
797–802 Reign of Irene
800 Coronation of Charlemagne
802–811 Reign of Nikephoros I
811 Reign of Staurakios
811–813 Reign of Michael I Rangabe
813–820 Reign of Leo V the Armenian
815 Iconoclasm revived by Leo V
820–829 Reign of Michael II
826 First Arab assault on Sicily
829–842 Reign of Theophilos
838 Arabs conquer Amorion and Ankyra
842–867 Reign of Michael III
843 Restoration of icons
860 First Rus attack on Constantinople
863 Mission of Constantine and Methodios to Moravia
867–886 Reign of Basil I
886–912 Reign of Leo VI
912–913 Reign of Alexander
913–959 Reign of Constantine VII, with Nicholas Mystikos (913–914) and Zoe Karbonopsina (914–920) as regents; Romanos I Lekapenos (920–944) and Romanos II (945–959) as co-emperors
954–958 John Tzimiskes and Nikephoros Phokas win victories across the Euphrates
959–963 Reign of Romanos II
961 Crete recaptured
963 Great Lavra monastery founded on Mount Athos
963–969 Reign of Nikephoros II Phokas
969–976 Reign of John I Tzimiskes
976–1025 Reign of Basil II (with co-emperor Constantine VIII)
988 Baptism of Vladimir I, prince of Kiev; defeat of Bardas Phokas
996 Legislation restricting acquisition of land by wealthy magnates from the poor
1014 Basil II defeats the Bulgars; death of Tsar Samuel
1025–1028 Reign of Constantine VIII
1028–1034 Reign of Romanos III Argyros
1034–1041 Reign of Michael IV Paphlagon
1040 George Maniakes captures Syracuse
1041 Revolt of Peter Deljan suppressed
1041–1042 Reign of Michael V Kalaphates
1042 Reign of Zoe and Theodora
1042–1055 Reign of Constantine IX Monomachos
1043 Rus attack Constantinople; rebellion of Maniakes
1045 Kingdom of Ani annexed
1046 University of Constantinople refounded
1047 Revolt of Leo Tornikos suppressed; Pechenegs cross the Danube and plunder Thrace
1054 Schism between the churches
1055–1056 Reign of Theodora (again)
1056–1057 Reign of Michael VI Stratiotikos
1057–1059 Reign of Isaac I Komnenos
1059–1067 Reign of Constantine X Doukas
1060 Norman conquest of Sicily begins
1064 Seljuks capture Ani
1064–1065 Uzes cross the Danube and raid Thrace
1067 Seljuks pillage Caesarea in Asia Minor
1068–1071 Reign of Romanos IV Diogenes
1071 Normans capture Bari; battle of Mantzikert
1071–1078 Reign of Michael VII Doukas
1072 Revolt of Constantine Bodin in Bulgaria
1073–1074 Revolt of Roussel de Bailleul
1078–1081 Reign of Nikephoros III Botaneiates
1081–1118 Reign of Alexios I Komnenos
1081–1085 Alexios campaigns against the Normans
1082 Venice granted commercial privileges; trial of John Italos
1088–1093 Tzachas attacks islands in the Aegean
1091 Normans complete their conquest of Sicily; Pechenegs defeated at Mt. Lebounion
1092 Monetary reform of Alexios I
1095–1099 First Crusade
1108 Treaty of Devol
1118–1143 Reign of John II Komnenos
1126 Venetian commercial privileges reaffirmed
1127–1129 Victories over the Serbs and the Hungarians
1132–1137 Victories over the Danishmends and the Rubenids in Asia Minor
1137 Antioch submits to John II
1143–1180 Reign of Manuel I Komnenos
1147–1198 Second Crusade
1147 Normans seize Kerkyra (retaken in 1149) and plunder Corinth and Thebes
1171 Venetians arrested and their property seized throughout the empire
1176 Battle of Myriokephalon
1180–1183 Reign of Alexios II Komnenos
1182 Latins massacred in Constantinople
1183–1185 Reign of Andronikos I Komnenos
1184 Cyprus falls to Isaac Komnenos
1185 Normans capture Thessalonike
1185–1195 Reign of Isaac II Angelos
1186 Second Bulgarian Empire founded
1187 Revolt of Alexios Branas
1187–1191 Third Crusade
1195–1203 Reign of Alexios III Angelos
1203–1204 Reign of Isaac II (again) and Alexios IV Angelos. Reign of Alexios V Doukas (“Mourtzouphlos”); Fourth Crusade conquers Constantinople
1204–1261 Latin Empire of Constantinople
1205–1221 Reign of Theodore I Laskaris
1221–1254 Reign of John III Vatatzes
1246 John III Vatatzes captures Thessalonike
1254–1258 Reign of Theodore II Laskaris
1258–1261 Reign of John IV Laskaris
1259 Battle of Pelagonia
1261 Reconquest of Constantinople
1261–1282 Reign of Michael VIII Palaiologos
1274 Council of Lyons; union of the churches
1282 Sicilian Vespers
1282–1328 Reign of Andronikos II Palaiologos
1302 Battle of Bapheus
1305 Roger de Flor assassinated
1311 Catalan Duchy of Athens and Thebes established
1321–1328 First civil war (between Andronikos II and Andronikos III)
1326 Ottomans conquer Prousa
1328–1341 Reign of Andronikos III Palaiologos
1330 Battle of Velbuzd
1331 Ottomans capture Nicaea
1341–1391 Reign of John V Palaiologos
1341–1347 Second civil war (between John V and John Kantakouzenos)
1342–1350 Zealot revolt in Thessalonike
1347–1354 Reign of John VI Kantakouzenos
1348–1349 Black Death ravages Constantinople
1354 Ottomans occupy Gallipoli
1355 Death of Stefan Urosh IV Dushan
1366 Amadeo VI of Savoy recovers Gallipoli
1369 John V’s journey to Rome
1376–1379 Reign of Andronikos IV Palaiologos
1382 Ottomans conquer Serdica (Sofia)
1387 Ottomans conquer Thessalonike
1389 Battle of Kosovo Polje
1390 Reign of John VII Palaiologos
1391–1425 Reign of Manuel II Palaiologos
1393 Ottomans conquer Bulgaria
1394 Ottomans capture Thessalonike again
1399–1403 Manuel II’s journey to the West
1402 Battle of Ankyra
1403 Byzantine recovery of Thessalonike
1422 Murad II besieges Constantinople
1423 Thessalonike surrenders to Venice
1425–1448 Reign of John VIII Palaiologos
1430 Ottomans reconquer Thessalonike
1438–1439 Council of Ferrara-Florence
1444 Crusade of Varna; Hexamilion restored
1449–1453 Reign of Constantine XI Palaiologos
1452 Constantine XI reaffirms the union of the churches;
Rumeli Hisar constructed
1453 Ottomans conquer Constantinople
1456 Ottomans conquer Athens
1460 Ottomans conquer Mistra
1461 Ottomans conquer Trebizond