<P> At the time, in the Medieval West, the title "empire" had a specific technical meaning that was exclusively applied to states that considered themselves the heirs and successors of the Roman Empire . Among these were the Byzantine Empire, which was the actual continuation of the Eastern Roman Empire, the Carolingian Empire, the largely Germanic Holy Roman Empire, and the Russian Empire . Yet, these states did not always fit the geographic, political, or military profiles of empires in the modern sense of the word . To legitimise their imperium, these states directly claimed the title of Empire from Rome . The sacrum Romanum imperium (Holy Roman Empire), which lasted from 800 to 1806, claimed to have exclusively comprehended Christian principalities, and was only nominally a discrete imperial state . The Holy Roman Empire was not always centrally - governed, as it had neither core nor peripheral territories, and was not governed by a central, politico - military elite . Hence, Voltaire's remark that the Holy Roman Empire "was neither holy, nor Roman, nor an empire" is accurate to the degree that it ignores German rule over Italian, French, Provençal, Polish, Flemish, Dutch, and Bohemian populations, and the efforts of the ninth - century Holy Roman Emperors (i.e., the Ottonians) to establish central control . Voltaire's "...nor an empire" observation applies to its late period . </P> <P> In 1204, after the Fourth Crusade conquered Constantinople, the crusaders established a Latin Empire (1204--1261) in that city, while the defeated Byzantine Empire's descendants established two smaller, short - lived empires in Asia Minor: the Empire of Nicaea (1204--1261) and the Empire of Trebizond (1204--1461). 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 . </P> <P> In the thirteenth century, Genghis Khan expanded the Mongol Empire to be the largest contiguous empire in the world . However, within two generations, the empire was separated into four discrete khanates under Genghis Khan's grandsons . One of them, Kublai Khan, conquered China and established the Yuan Dynasty with the imperial capital at Beijing . One family ruled the whole Eurasian land mass from the Pacific to the Adriatic and Baltic Seas . The emergence of the Pax Mongolica had significantly eased trade and commerce across Asia . </P> <P> In the pre-Columbian America, two Empires were prominents--the Azteca in Mesoamerica and Inca in Peru . Both existed for several generations before the arrival of the Europeans . Inca had gradually conquered the whole of the settled Andean world as far south as today Santiago in Chile . </P>

By the 13th century the blank was the largest land empire at that point