question: Why is the fall of the Roman empire considered the turning point between antiquity and the European middle ages, and why is the fall of Constantinople considered the turning point between the middle ages and the Renaissance?
comment: They're not, really. In either case, they're convenient rules of thumb if you're just trying to do some very coarse divisions of the last 2000 years into eras, but it's just a loose convention to organize European history, not something with real historical meaning. & #x200B; Also, Constantinople is only very rarely used to mark that boundary, which is usually a century or so earlier. & #x200B; & #x200B;
passages: The migration waves of Byzantine scholars and émigrés in the period following the sacking of Constantinople and the fall of Constantinople in 1453 is considered by many scholars key to the revival of Greek and Roman studies that led to the development of the Renaissance humanism and science. These émigrés were grammarians, humanists, poets, writers, printers, lecturers, musicians, astronomers, architects, academics, artists, scribes, philosophers, scientists, politicians and theologians. They brought to Western Europe the far greater preserved and accumulated knowledge of their own (Greek) civilization.
  
  Section::::Cultural references.:Renaming of the city.
   For some time Greek scholars had gone to Italian city-states, a cultural exchange begun in 1396 by Coluccio Salutati, chancellor of Florence, who had invited Manuel Chrysoloras, a Byzantine scholar to lecture at the University of Florence. After the conquest many Greeks, such as John Argyropoulos and Constantine Lascaris, fled the city and found refuge in the Latin West, bringing with them knowledge and documents from the Greco-Roman tradition to Italy and other regions that further propelled the Renaissance. Those Greeks who stayed behind in Constantinople mostly lived in the Phanar and Galata districts of the city. The Phanariotes, as they were called, provided many capable advisers to the Ottoman rulers.
   On 29 May 1453, the then-emergent Ottoman Empire conquered the city of Constantinople following a lengthy campaign wherein the Ottomans constructed fortifications on each side of the strait, the Anadoluhisarı (1393) and the Rumelihisarı (1451), in preparation for not only the primary battle but to assert long-term control over the Bosporus and surrounding waterways. The final 53-day campaign, which resulted in Ottoman victory, constituted an important turn in world history. Together with Christopher Columbus's first voyage to the Americas in 1492, the 1453 conquest of Constantinople is commonly noted as among the events that brought an end to the Middle Ages and marked the transition to the Renaissance and the Age of Discovery.
   29 May 1453, the day of the fall of Constantinople, fell on a Tuesday, and since then Tuesday has been considered an unlucky day by Greeks generally.
  
  Section::::Cultural references.:Impact on the Renaissance.
   Some observers have called into question whether the Renaissance was a cultural "advance" from the Middle Ages, instead seeing it as a period of pessimism and nostalgia for classical antiquity, while social and economic historians, especially of the "longue durée", have instead focused on the continuity between the two eras, which are linked, as Panofsky observed, "by a thousand ties". 
   As the postclassical era drew to a close in the 15th century, many of the empires established throughout the period were in decline. The Byzantine Empire would soon be overshadowed in the Mediterranean by Italian city states such as Venice and Genoa and the Ottoman Turks. The Byzantines faced repeated attacks from eastern and western powers during the Fourth Crusade, and declined further until the loss of Constantinople to the Ottoman Turks in 1453.
   The Fall of Constantinople in 1453 fuelled the era later commonly known as the "Italian Renaissance". During this period, refugee Byzantine scholars were principally responsible for carrying, in person and in writing, ancient Greek grammatical, literary studies, mathematical, and astronomical knowledge to early Renaissance Italy. They also brought with them classical learning and texts on botany, medicine and zoology, as well as the works of Dioscorides and John Philoponus' criticism of Aristotelian physics.
  
  Section::::Culture.
  
  Section::::Culture.:Religion.
   It was also a watershed moment in military history. Since ancient times, cities had used ramparts and city walls to protect themselves from invaders, and Constantinople's substantial fortifications had been a model followed by cities throughout the Mediterranean region and Europe. The Ottomans ultimately prevailed due to the use of gunpowder (which powered formidable cannons).
  
  The conquest of the city of Constantinople and the end of the Byzantine Empire was a key event in the Late Middle Ages which also marks, for some historians, the end of the Medieval period.
  
  Section::::State of the Byzantine Empire.
   Following the Mongols from Central Asia came the Ottoman Turks. By 1400 they had captured most of modern-day Turkey and extended their rule into Europe through the Balkans and as far as the Danube, surrounding even the fabled city of Constantinople. Finally, in 1453, one of Europe's greatest cities fell to the Turks. The Ottomans under the command of Sultan Mehmed II, fought a vastly outnumbered defending army commanded by Emperor Constantine XI — the last "Emperor of the Eastern Roman Empire" — and blasted down the ancient walls with the terrifying new weaponry of the canon. The Ottoman conquests sent refugee Greek scholars westward, contributing to the revival of the West's knowledge of the learning of Classical Antiquity.
   BULLET::::- Emerson, Charles. "1913: In Search of the World Before the Great War" (2013) compares Constantinople to 20 major world cities; pp 358-80.
  
  BULLET::::- Korolija Fontana-Giusti, Gordana 'The Urban Language of Early Constantinople: The Changing Roles of the Arts and Architecture in the Formation of the New Capital and the New Consciousness' in "Intercultural Transmission in the Medieval Mediterranean", (2012), Stephanie L. Hathaway and David W. Kim (eds), London: Continuum, pp 164–202. .
   Constantinople came into prominence only after the early Christian period, being founded officially in 330, five years after the First Council of Nicaea, though the much smaller original city of Byzantium was an early center of Christianity largely due to its proximity to Anatolia.
  
  The community and seat of the patriarchate according to Orthodox tradition was founded by St Peter and then given to St. Ignatius, in what is now Turkey.
  
  Section::::Diversity and proto-orthodoxy.:Proto-orthodoxy.:Rome and the Papacy.
   The concept of “renaissance” has been deeply studied by the French philosopher Rémi Brague. Brague thinks that the characteristic that best defines the Roman world - and its heiress, Western Europe - is its “eccentricity” or external position (secondarité) with respect to the Jewish and Christian tradition of Jerusalem and the classical Greek tradition of Athens. The Romans were deeply aware of their cultural debt to the Greek world, which is to say that they were aware that their culture was animated by a source that was not their own. That the medieval heirs of the Western (Roman) Empire inherited this eccentric character can be seen in the fact that Latin Christianity has always known itself to be rooted in Athens and Jerusalem, as authentic sources of Latin/Western culture.
   The Eastern Roman empire's capital city of Constantinople was left as the only unconquered large urban center of the original Roman empire, as well as being the largest city in Europe. Over the next millennium the Roman culture of that city would slowly change, leading modern historians to refer to it by a new name, Byzantine, though many classical books, sculptures, and technologies survived there along with classical Roman cuisine and scholarly traditions, well into the Middle Ages, when much of it was "rediscovered" by visiting Western crusaders. Indeed, the inhabitants of Constantinople continued to refer to themselves as Romans, as did their eventual conquerors in 1453, the Ottomans. (See Rûm and Romaioi.) The classical scholarship and culture that was still preserved in Constantinople was brought by refugees fleeing its conquest in 1453 and helped to spark the Renaissance, see Greek scholars in the Renaissance.
   The transfer of the capital of the empire from Rome to Constantinople in 330 enabled the latter to free itself from its ecclesiastical dependency on Heraclea and in little more than half a century to obtain this recognition of next-after-Rome ranking from the first Council held within its walls. Alexandria's objections to Constantinople's promotion, which led to a constant struggle between the two sees in the first half of the 5th century, were supported, at least until the Fourth Council of Constantinople of 869–870, by Rome, which proposed the theory that the most important sees were the three Petrine ones, with Rome in first place.
   After the sack, many feared other European Christian kingdoms would suffer the same fate as Constantinople. Two possible responses emerged amongst the humanists and churchmen of that era: Crusade or dialogue. Pope Pius II strongly advocated for another Crusade, while Nicholas of Cusa supported engaging in a dialogue with the Ottomans.
   Many writers have attempted to put a specific date on the symbolic "end" of antiquity with the most prominent dates being the deposing of the last Western Roman Emperor in 476, the closing of the last Platonic Academy in Athens by the Eastern Roman Emperor Justinian I in 529, and the conquest of much of the Mediterranean by the new Muslim faith from 634-718. These Muslim conquests, of Syria (637), Egypt (639), Cyprus (654), North Africa (665), Hispania (718), Southern Gaul (720), Crete (820), and Sicily (827), Malta (870) (and the sieges of the Eastern Roman capital, First Arab Siege of Constantinople (674–78) and Second Arab Siege of Constantinople (717–18)) severed the economic, cultural, and political links that had traditionally united the classical cultures around the Mediterranean, ending antiquity (see Pirenne Thesis).
   The struggle for East-West union at Ferrara and Florence, while promising, never bore fruit. While progress toward union in the East continued to be made in the following decades, all hopes for a proximate reconciliation were dashed with the fall of Constantinople in 1453. Following their conquest, the Ottomans encouraged hardline anti-unionist Orthodox clerics in order to divide European Christians.
  
  Perhaps the council's most important historical legacy was the lectures on Greek classical literature given in Florence by many of the delegates from Constantinople, including the renowned Neoplatonist Gemistus Pletho. These greatly helped the progress of Renaissance humanism.
  
  Section::::See also.
   Section::::Constantinople.
  
  Constantinople was built as the second Rome by Emperor Constantine in 330 AD.
   From the 9th through the end of the 12th century, Constantinople, capital of the Byzantine Empire, was the largest and wealthiest city in Europe, with a population approaching 1 million. Following the Byzantine–Ottoman wars and other conflicts, the Ottoman Empire gained control over many cities in the Mediterranean area, including Constantinople in 1453.
   Ultimately, it was a slow, complex, and graduated change in the socioeconomic structure in European history that led to the changeover between Classical Antiquity and Medieval society and no specific date can truly exemplify that.
  
  Section::::Political revivalism.
   Constantinople, in what is today Turkey, then the capital of the Christian Byzantine Empire, falls to the emerging Muslim Ottoman Turks, marking the end of the tremendously influential Byzantine Empire and, for some historians, the end of the Middle Ages. The event forced Western Europeans to find a new trade route, adding further momentum to what was the beginning of the Age of Discovery, which would lead to the global mapping of the world. Explorations by the Portuguese and Spanish led to European sightings of the Americas (the New World) and the sea passage along Cape of Good Hope to India, in the last decade of the century. These expeditions ushered in the era of the Portuguese and Spanish colonial empires.
   Constantinople was retaken in 1261 by the Byzantine successor state centered in Nicaea, re-establishing the Byzantine Empire until 1453, by which time the Turkish-Muslim Ottoman Empire (ca. 1300–1918), had conquered most of the region. The Ottoman Empire was a successor of the Abbasid Empire and it was the most powerful empire to succeed the Abbasi empires at the time, as well as one of the most powerful empires in the world. The Ottoman Empire centered on modern day Turkey, dominated the eastern Mediterranean, overthrew the Byzantine Empire to claim Constantinople and it would start battering at Austria and Malta, which were countries that were key to central and to south-west Europe respectively — mainly for their geographical location. The reason these occurrences of batterings were so important was because the Ottomans were Muslim, and the rest of Europe was Christian, so there was a sense of religious fighting going on. This was not just a rivalry of East and West but a rivalry between Christians and Muslims. Both the Christians and Muslims had alliances with other countries, and they had problems in them as well. The flows of trade and of cultural influences across the supposed great divide never ceased, so the countries never stopped bartering with each other. These epochal clashes between civilizations profoundly shaped many people's thinking back then, and continues to do so in the present day. Modern hatred against Muslim communities in South-Eastern Europe, mainly in Bosnia and Kosovo, has often been articulated in terms of seeing them as unwelcome residues of this imperialism: in short, as Turks. Moreover, Eastern Orthodox imperialism was not re-established until the coronation of Peter the Great as Emperor of Russia in 1721. Likewise, with the collapse of the Holy Roman Empire in 1806 during the Napoleonic Wars (1803–1815), the Austrian Empire (1804–1867) emerged reconstituted as the Empire of Austria–Hungary (1867–1918), having "inherited" the imperium of Central and Western Europe from the losers of said wars. 
   In the 14th century, starting from Italy and then spreading throughout Europe, there was a massive artistic, architectural, scientific and philosophical revival, as a result of the Christian revival of Greek philosophy, and the long Christian medieval tradition that established the use of reason as one of the most important of human activities. This period is commonly referred to as the Renaissance. In the following century, this process was further enhanced by an exodus of Greek Christian priests and scholars to Italian cities such as Venice after the end of the Byzantine Empire with the fall of Constantinople.
   Numerous items, however, are simplified: the doges were appointed for life but the Ten served only one-year terms and could only have a single family member serving at a time. The Republic of Venice maintained its allegiance to Rome throughout the Western Schism but the earlier Avignon Papacy goes unmentioned. Cities only occasionally and randomly close themselves to trade. Florence is treated as a seaport in place of Pisa and Constantinople is given its earlier and terser name Byzantium.
   During the High Middle Ages (c. 1000–1300), Christian-oriented art and architecture flourished and the Crusades were mounted to recapture the Holy Land from Muslim control. The influence of the emerging nation-state was tempered by the ideal of an international Christendom and the presence of the Roman Catholic Church in all western kingdoms. The codes of chivalry and courtly love set rules for proper behavior, while the Scholastic philosophers attempted to reconcile faith and reason. The age of Feudalism would be dramatically transformed by the cataclysm of the Black Death and its aftermath. This time would be a major underlying cause for the Renaissance. By the turn of the 16th century European or Western Civilization would be engaging in the Age of Discovery.
  
presuppositions: The fall of the Roman empire and Constantinople are turning points in history. The falls of the Roman empire and Constantinople are considered the turning points of their respective ages.
corrections: The fall of the Roman empire and Constantinople are just loose conventions to organize European history. The falls of the Roman empire and Constantinople are just convenient rules of thumb when marking their respective ages.
raw_presuppositions: The fall of the Roman empire and Constantinople are turning points in history. The falls of the Roman empire and Constantinople are considered the turning points of their respective ages.
raw_corrections: The fall of the Roman empire and Constantinople are just loose conventions to organize European history. The falls of the Roman empire and Constantinople are just convenient rules of thumb when marking their respective ages.