II took to the throne, the army fell apart and the Byzantines suffered regular defeats at the hands of their eastern opponents, although they would continue to enjoy success against the crusader territories in Greece. By c. 1350, following a destructive civil war and the outbreak of the Black Death, the Empire was no longer capable of raising troops and the supplies to maintain them. The Empire came to rely upon troops provided by Serbs, Bulgarians, Venetians, Latins, Genoans and Ottoman Turks to fight the civil wars that lasted for the greater part of the 14th century, with the latter foe being the most successful in establishing a foothold in Thrace. The Ottomans swiftly expanded through the Balkans and cut off Constantinople, the capital of the Byzantine Empire, from the surrounding land. The last decisive battle was fought by the Palaiologan army in 1453, when Constantinople was besieged and fell on 29 May. The last isolated remnants of the Byzantine state were conquered by 1461. See also This article contains the summaries of the detailed linked articles on the historical phases above, Readers seeking discussion of the Roman army by theme, rather than by chronological phase, should consult the following articles: History Campaign history of the Roman military Military history of ancient Rome Political history of the Roman military Structural history of the Roman military Technological history of the Roman military Corps Praetorian Guard Roman legion Roman auxiliaries Roman cavalry Roman navy Strategy and tactics Roman infantry tactics Strategy of the Roman military Equipment Ancient Roman military clothing Roman military personal equipment Other Economics of the Roman army Roman military engineering Roman military frontiers and fortifications Roman military decorations and punishments References External links Ross Cowan, Roman Legionary 109-58 BC: The Age of Marius, Sulla and Pompey the Great Diocletian and the Roman Army Life of Roman legionary Roman Warriors: The Myth of the Military Machine Called to the Eagle: Some Sullan Centurions Military of ancient Rome