The hundred years from the accession of Alexios I Komnenos in April 1081 to the death of Manuel I Komnenos in September 1180 were a restoration of the empire's military, fiscal and diplomatic position from the catastrophe of the immediate post-Macedonian collapse. The three Komnenian emperors — Alexios I (1081–1118), John II (1118–1143), and Manuel I (1143–1180) — reconstructed the imperial state on a new institutional pattern, recovered the western and coastal portions of Anatolia from the Seljuks (with assistance from the First Crusade and its successors), restored the Empire's diplomatic standing in the Latin West, and defended the Balkan and Italian frontiers. The achievement was undone by the succession crisis after Manuel's death in 1180, which produced the political conditions for the catastrophe of the Fourth Crusade in 1204.
Manzikert and the loss of Anatolia
The proximate cause of the Komnenian rebuilding was the military disaster at Manzikert in August 1071 — the defeat of the imperial field army under Romanos IV Diogenes by the Seljuk sultan Alp Arslan in the upper Euphrates valley. The battle was followed within a decade by the Seljuk and Turcoman occupation of the central and eastern Anatolian plateau, the loss of the imperial heartland that had provided the recruiting base for the thematic armies, and the reduction of the imperial position in Asia to a coastal strip. The reigns of Michael VII Doukas (1071–78) and Nikephoros III Botaneiates (1078–81) were unable to reverse the collapse; civil wars among the candidates for the throne produced further fragmentation.
Alexios I and the Komnenian system
Alexios I, who seized the throne in April 1081 from Nikephoros III by a coup of the Komnenos-Doukas family alliance, undertook a reconstruction of the imperial system on a different institutional pattern. The Komnenian reforms produced: the replacement of the thematic militia by a professional standing army of approximately twenty thousand men, predominantly mercenary in composition (Frankish, Norman, English, Armenian and Pecheneg contingents); the reorganisation of the senior imperial titulature into a hierarchy of family titles (sebastokrator, panhypersebastos, protosebastos, megas doux, megas domestikos) granted predominantly to members of the Komnenos extended family and its marital allies; the reform of the imperial currency (the introduction of the gold hyperpyron, replacing the debased nomisma of the late Macedonian period); and the integration of the great landed magnates (the dynatoi) into the imperial political system through grants of pronoia (revocable land grants in exchange for military service).
The First Crusade
The diplomatic intervention by which Alexios most reshaped the Empire's strategic situation was his 1095 appeal to Pope Urban II for Latin military assistance against the Seljuks. The diplomatic intent was the recruitment of European mercenary forces to be integrated into the imperial military system. The result — the Council of Clermont of November 1095 and the preaching of the First Crusade — exceeded Roman expectations by a margin. The Crusader armies that arrived at Constantinople between December 1096 and May 1097 (substantially under Godfrey of Bouillon, Raymond of Toulouse, Bohemond of Taranto, and others) comprised approximately fifty thousand combatants, better-equipped and more independently-led than Alexios had anticipated.
The Roman diplomatic and military operations of 1097–99 were successful in extracting the benefits of the Crusade while containing its liabilities. The Crusaders were required to take oaths of fealty to Alexios for any territories they recovered from the Seljuks. The Roman naval and logistical support for the Crusader sieges of Nicaea (May–June 1097) and Antioch (October 1097–June 1098) was substantial. The Roman recovery of Nicaea, Smyrna, Ephesus, Sardis and the western Anatolian coast in 1097–99 was the direct benefit of the Crusade. The subsequent dispute over Antioch — the Norman seizure of the city under Bohemond in June 1098 in breach of the prior oath — was the source of subsequent diplomatic conflict between the Empire and the Crusader states.
John II Komnenos
John II Komnenos (1118–1143), Alexios's son and successor, was widely regarded by both contemporary and subsequent assessment as the finest emperor of the dynasty. The reign was characterised by military operations on multiple frontiers: the campaigns against the Pechenegs (1122, producing their elimination as a military threat), the Hungarian wars (1127–29), the Serbian operations (1129), the Anatolian reconquests against the Danishmend Turks (1130s — the recovery of Kastamonu and Gangra), and the Cilician and Syrian operations (1137–38 — campaigns against the Armenian principality of Cilicia and demands on the Crusader principalities of Antioch and Edessa). The result was the restoration of Roman authority in coastal Anatolia and the Levant. John died in April 1143 from a accidental hunting wound on the Cilician plain.
Manuel I and the Latin alliance
Manuel I (1143–1180), John's younger son who was elevated to the throne over the claim of his elder brother Isaac, prosecuted a diplomatic policy of integration with the Latin Christian states. The dynastic marriages — Manuel's first wife was Bertha of Sulzbach (sister-in-law of Conrad III of Germany); his second was Maria of Antioch (daughter of Raymond of Poitiers); his daughter Maria Komnene married Renier of Montferrat — tied the Roman imperial house to the principal European dynastic networks. The diplomatic accommodation with Venice (the 1126 commercial privileges renewed and extended) integrated the Venetian merchant marine into the imperial supply system. The doctrinal-religious accommodation produced discussions of reunion with the Roman papacy (substantially unsuccessful, but in their willingness to take the question seriously).
The military operations of Manuel's reign included the 1158 expedition against the Norman Kingdom of Sicily, the 1167 victory over the Hungarians at Sirmium, and the 1176 Anatolian campaign that ended in the Roman defeat at Myriokephalon by the Seljuk sultan Kilij Arslan II. The Myriokephalon defeat — the destruction of the imperial Anatolian field army in a mountain ambush — terminated the Komnenian programme of Anatolian reconquest. Manuel died in September 1180. The subsequent regency for his eleven-year-old son Alexios II under the unpopular Maria of Antioch produced the 1182 Latin massacre at Constantinople (the popular slaughter of approximately sixty thousand Italian residents of the capital) and the usurpation of Andronikos I Komnenos in 1183. The Komnenian dynasty effectively ended with Andronikos's murder in 1185. The decay of the imperial position over the subsequent two decades produced the conditions for the Fourth Crusade's sack of Constantinople in 1204, to which we now turn.
End of Chapter VI