Alexios III Angelos, Latinized as Alexius III Angelus, was Byzantine Emperor from March 1195 to 17/18 July 1203. He reigned under the name Alexios Komnenos associating himself with the Komnenos dynasty. A member of the extended imperial family, Alexios came to the throne after deposing, blinding and imprisoning his younger brother Isaac II Angelos. The most significant event of his reign was the attack of the Fourth Crusade on Constantinople in 1203, on behalf of Alexios IV Angelos. Alexios III took over the defence of the city, which he mismanaged, and then fled the city at night with one of his three daughters. From Adrianople, and then Mosynopolis, he attempted unsuccessfully to rally his supporters, only to end up a captive of Marquis Boniface of Montferrat. He was ransomed and sent to Asia Minor where he plotted against his son-in-law Theodore I Laskaris, but was eventually captured and spent his last days confined to the Monastery of Hyakinthos in Nicaea, where he died.
Alexios V Doukas, Latinized as Alexius V Ducas, was Byzantine emperor from February to April 1204, just prior to the sack of Constantinople by the participants of the Fourth Crusade. His family name was Doukas, but he was also known by the nickname Mourtzouphlos or Murtzuphlus (Μούρτζουφλος), referring to either bushy, overhanging eyebrows or a sullen, gloomy character. He achieved power through a palace coup, killing his predecessors in the process. Though he made vigorous attempts to defend Constantinople from the crusader army, his military efforts proved ineffective. His actions won the support of the mass of the populace, but he alienated the elite of the city. Following the fall, sack, and occupation of the city, Alexios V was blinded by his father-in-law, the ex-emperor Alexios III, and later executed by the new Latin regime. He was the last Byzantine emperor to rule in Constantinople until the Byzantine recapture of Constantinople in 1261.
Constantinople became the capital of the Roman Empire during the reign of Constantine the Great in 330. Following the collapse of the Western Roman Empire in the late 5th century, Constantinople remained the capital of the Eastern Roman Empire, the Latin Empire (1204–1261), and the Ottoman Empire (1453–1922). Following the Turkish War of Independence, the Turkish capital then moved to Ankara. Officially renamed Istanbul in 1930, the city is today the largest city in Europe, straddling the Bosporus strait and lying in both Europe and Asia, and the financial centre of Turkey.
Theodore I Laskaris or Lascaris was the first emperor of Nicaea—a successor state of the Byzantine Empire—from 1205 to his death. Although he was born to an obscure aristocratic family, his mother was related to the imperial Komnenos clan. He married Anna, a younger daughter of Emperor Alexios III Angelos in 1200. He received the title of despot before 1203, demonstrating his right to succeed his father-in-law on the throne.
The fall of Constantinople, also known as the conquest of Constantinople, was the capture of the capital of the Byzantine Empire by the Ottoman Empire. The city was captured on 29 May 1453 as part of the culmination of a 53-day siege which had begun on 6 April.
The Fourth Crusade (1202–1204) was a Latin Christian armed expedition called by Pope Innocent III. The stated intent of the expedition was to recapture the Muslim-controlled city of Jerusalem, by first defeating the powerful Egyptian Ayyubid Sultanate. However, a sequence of economic and political events culminated in the Crusader army's 1202 siege of Zara and the 1204 sack of Constantinople, rather than the conquest of Egypt as originally planned. This led to the Partitio terrarum imperii Romaniae or the partition of the Byzantine Empire by the Crusaders and their Venetian allies leading to a period known as Frankokratia, or "Rule of the Franks" in Greek.
The Latin Empire, also referred to as the Latin Empire of Constantinople, was a feudal Crusader state founded by the leaders of the Fourth Crusade on lands captured from the Byzantine Empire. The Latin Empire was intended to replace the Byzantine Empire as the Western-recognized Roman Empire in the east, with a Catholic emperor enthroned in place of the Eastern Orthodox Roman emperors. The main objective of the Latin Empire was planned by Venice, which promoted the creation of this state for their self-benefit.
Alexios IV Angelos, Latinized as Alexius IV Angelus, was Byzantine Emperor from August 1203 to January 1204. He was the son of Emperor Isaac II Angelos and his first wife, an unknown Palaiologina, who became a nun with the name Irene. His paternal uncle was his predecessor Emperor Alexios III Angelos.
Theodore Branas or Vranas, sometimes called Theodore Komnenos Branas, was a general under the Byzantine Empire and afterwards under the Latin Empire of Constantinople. Under the Latin regime he was given the title Caesar and in 1206 he became governor and lord of Adrianople. He is called Livernas by western chroniclers of the Fourth Crusade, including Geoffroi de Villehardouin.
The Empire of Nicaea or the Nicene Empire was the largest of the three Byzantine Greek rump states founded by the aristocracy of the Byzantine Empire that fled when Constantinople was occupied by Western European and Venetian armed forces during the Fourth Crusade, a military event known as the Sack of Constantinople. Like the other Byzantine rump states that formed due to the 1204 fracturing of the empire, such as the Empire of Trebizond and the Despotate of Epirus, it was a continuation of the eastern half of the Roman Empire that survived well into the medieval period. A fourth state, known in historiography as the Latin Empire, was established by an army of Crusaders and the Republic of Venice after the capture of Constantinople and the surrounding environs.
Constantine Laskaris may have been Byzantine Emperor for a few months from 1204 to early 1205. He is sometimes called "Constantine XI", a numeral now usually reserved for Constantine Palaiologos.
The Byzantine Empire was ruled by emperors of the Angelos dynasty between 1185 and 1204 AD. The Angeloi rose to the throne following the deposition of Andronikos I Komnenos, the last male-line Komnenos to rise to the throne. The Angeloi were female-line descendants of the previous dynasty. While in power, the Angeloi were unable to stop the invasions of the Turks by the Sultanate of Rum, the uprising and resurrection of the Bulgarian Empire, and the loss of the Dalmatian coast and much of the Balkan areas won by Manuel I Komnenos to the Kingdom of Hungary.
The Palaiologan army refers to the military forces of the Byzantine Empire under the rule of the Palaiologos dynasty, from the late 13th century to its final collapse in the mid-15th century. The army was a direct continuation of the forces of the Empire of Nicaea, which itself was a fractured component of the formidable Komnenian army of the 12th century. Under the first Palaiologan emperor, Michael VIII, the army's role took an increasingly offensive role whilst the naval forces of the empire, weakened since the days of Andronikos I Komnenos, were boosted to include thousands of skilled sailors and some 80 ships. Due to the lack of land to support the army, the empire required the use of large numbers of mercenaries.
This history of the Byzantine Empire covers the history of the Eastern Roman Empire from late antiquity until the Fall of Constantinople in 1453 AD. Several events from the 4th to 6th centuries mark the transitional period during which the Roman Empire's east and west divided. In 285, the emperor Diocletian partitioned the Roman Empire's administration into eastern and western halves. Between 324 and 330, Constantine I transferred the main capital from Rome to Byzantium, later known as Constantinople and Nova Roma. Under Theodosius I, Christianity became the Empire's official state religion and others such as Roman polytheism were proscribed. Finally, under the reign of Heraclius, the Empire's military and administration were restructured and adopted Greek for official use instead of Latin. Although the Roman state continued, some historians choose to distinguish the Byzantine Empire from the earlier Roman Empire due to the imperial seat moving from Rome to Byzantium, the Empire’s integration of Christianity, and the predominance of Greek instead of Latin.
The Siege of Constantinople in 1203 was a crucial episode of the Fourth Crusade, marking the beginning of a series of events that would ultimately lead to the fall of the Byzantine capital. The crusaders, diverted from their original mission to reclaim Jerusalem, found themselves in Constantinople, in support of the deposed emperor Isaac II Angelos and his son Alexios IV Angelos. The besieging forces, primarily composed of Western European knights faced initial setbacks, but their determination and advanced siege weaponry played a pivotal role in pressuring the Byzantine defenders.
The Massacre of the Latins was a large-scale massacre of the Roman Catholic inhabitants of Constantinople, the capital of the Eastern Roman Empire, by the Eastern Orthodox population of the city in April 1182.
The Partitio terrarum imperii Romaniae, or Partitio regni Graeci, was a treaty signed among the crusaders after the sack of the Byzantine capital, Constantinople, by the Fourth Crusade in 1204. It established the Latin Empire and arranged the nominal partition of the Byzantine territory among the participants of the Crusade, with the Republic of Venice being the greatest titular beneficiary. However, because the crusaders did not in fact control most of the Empire, local Byzantine Greek nobles established a number of Byzantine successor kingdoms. As a result, much of the crusaders' declared division of the Empire amongst themselves could never be implemented. The Latin Empire established by the treaty would last until 1261, when the Empire of Nicaea reconquered Constantinople, re-establishing the Byzantine Empire. The various crusader principalities in southern Greece and the Aegean archipelago would last much longer, until they were conquered by the Ottomans in the 14th and 15th centuries.
This is a timeline of the presence of Eastern Orthodoxy in Greece from 1204 to 1453. The history of Greece traditionally encompasses the study of the Greek people, the areas they ruled historically, as well as the territory now composing the modern state of Greece.
The timeline of the Latin Empire is a chronological list of events of the history of the Latin Empire—the crusader state that developed on the ruins of the Byzantine Empire after the Fourth Crusade in the 13th century.
A reason for the longevity of the Byzantine Empire is how they managed their foreign relations. Armed combat and later its navy were the primary methods with the evolved traditions of the Roman Empire, however Byzantine diplomacy which eventuated with their many treaties was used extensively as well.
Crusaders 
Republic of Venice 
Byzantine Empire 
