Alternative theories of the location of Great Moravia propose that the core territory of "Great Moravia", a 9th-century Slavic polity, was not (or was only partly) located in the region of the northern Morava River (in present-day Czech Republic). Moravia emerged after the fall of the Avar Khaganate in the early . It flourished during the reign of Svatopluk I in the second half of the century, but collapsed in the first decade of the . "Great Moravia" was regarded as an archetype of Czechoslovakia, the common state of the Czechs and Slovaks, in the , and its legacy is mentioned in the preamble to the Constitution of Slovakia.
Several aspects of its history (including its territorial extension and political status) are the subject of scholarly disputes. A debate about the location of its core territory began in the second half of the . Imre Boba proposed that the center of Moravia was located near the southern Morava River (in present-day Serbia). Most specialists (including Herwig Wolfram and Florin Curta) rejected Boba's theory, but it was further developed by other historians, including Charles Bowlus and Martin Eggers. In addition to the theory of a "southern Moravia", new theories were proposed, arguing for the existence of two Moravias, called "Greater and Lesser Moravia", or arguing that the center of Moravia was at the confluence of the rivers Tisza and Mureș. Archaeological evidence does not support the alternative theories, because the existence of 9th-century power centers can only be documented along the northern Morava River, in accordance with the traditional view. However, scholars who accept the traditional view of a "northern Moravia" have not fully explained some of the contradictions between the written sources and archaeological evidence. For instance, written sources suggest a southward movement of the armies when mentioning the invasion of Moravia from the Duchy of Bavaria.
Great Moravia
The Moravians emerged as an individual Slavic tribe after the fall of the Avar Khaganate in the early . The first reference to them was recorded in the year in the Royal Frankish Annals. More than a century later, the Byzantine Emperor Constantine Porphyrogenitus mentioned their realm as "Megale Moravia", or "Great Moravia". The name, which is not mentioned in other primary sources, has been interpreted in various way. "Megale" may refer either to a territory which was located "further away" from Constantinople or to a former polity that had disappeared by the middle of the .
The first known Moravian ruler, Mojmir I, assisted the rebellious subjects of Louis the German, the King of East Francia, several times. During his reign, priests came from the Bishopric of Passau (a suffragan of the Archdiocese of Salzburg) to proselytize among the Moravians. Louis the German expelled Mojmir from Moravia in 846. In an attempt to diminish the influence of the German clerics, Mojmir's nephew and successor, Rastislav, requested priests from the Byzantine Empire in the early 860s. Emperor Michael III and Patriarch Photius sent two brothers, Saints Cyril and Methodius, to Moravia. The brothers started to translate liturgical texts into Old Church Slavonic in Moravia. Methodius, who survived his brother, was consecrated as archbishop by Pope Hadrian II in Rome in 869. Under the pope's decision, Moravia, the realm of Rastislav's nephew, Svatopluk, and the Pannonian domains of Koceľ fell within Methodius's jurisdiction, which caused conflicts with the archbishops of Salzburg.
Louis the German occupied Moravia and dethroned Rastislav, and the Bavarian prelates imprisoned Methodius in 870. Svatopluk united his realm with Moravia around 871 and expanded the territory under his rule during the next decades. Methodius was set free on Pope John VIII's demand in 873. However, after his death in 885, his disciples were expelled from Moravia. Svatopluk died in 894. His realm disintegrated because internal conflicts emerged after his death. The Magyars who settled in the Carpathian Basin around 895 destroyed Moravia in the first decade of .
Development of alternative theories
The systematic study of the history of Moravia began in the , influenced by the ideas of Romanticism and Pan-Slavism. Scholarly discussions have also been colored by political debates for centuries. After the establishment of Czechoslovakia in 1918, "Great Moravia" was regarded as an archetype of the common state of the Czechs and Slovaks. The Czechoslovak delegates referred to it when arguing for the recognition of the new state. In 1963, official celebrations of the eleventh centenary of the mission of Constantine and Methodius in Czechoslovakia emphasized the continuity between the early medieval state and its modern successor. A reference to "Great Moravia" can be found in the preamble to both the 1948 Constitution of the Czechoslovak Republic and the 1992 Constitution of Slovakia.
Several aspects of the history of Moravia are subjects of scholarly debate. Most modern scholars question earlier historians' descriptions of a "Great Moravian empire" with huge territories permanently integrated within it. Studies published from the 1990s also dispute the argument that Moravia reached the level of an early medieval state (a lasting and stable polity) during its history.
According to the traditional view, Moravia's core territory was located along the northern Morava River, a tributary of the Danube in present-day Czech Republic. Juraj Sklenár, an 18th-century Slovak historian, was the first to propose an alternative location; he argued that Moravia had originally been centered around Sirmium (now Sremska Mitrovica in Serbia), from where it expanded to the north to the lands that now form the Czech Republic and Slovakia. In 1813 Slovene philologist Jernej Kopitar elaborated this hypothesis proposing that Moravia actually was the name of a city. Nine years later Austrian historian Friedrich Blumberger supported the theory, polemicizing with Josef Dobrovský, a stanch opponent of the theory, over the original dates of the Cyril and Methodius veneration in the territory of modern Czechia and Slovakia and over the course of this dispute he reiterated Kopitar's arguments that Moravia should have been a city. After the death of Dobrovský in 1829 the dispute naturally ceased, and the theory was forgotten for more than a century; Italian linguist Sergio Bonazza argued in 2008 that this was caused by the fact that an influential Croatian Slavic scholar Vatroslav Jagić, a supporter of the conventional theory and the publisher of Kopitar–Dobrovský correspondence, harshly criticized the former, omissed most of his arguments from the historical monograph Istoriya slavyanskoy filologii (History of Slavic Philology) and mentioned Blumberger only in the context of Dobrovský's claim that he was Kopitar's assumed name.
Imre Boba was the first historian in the to challenge the traditional view. After studying the primary sources, he concluded that Moravia's core territory lay near the southern Morava River, around Sirmium. He published his theory in a monograph (Moravia's History Reconsidered: A Reinterpretation of Medieval Sources) in 1971. Most Central European historians (including Herwig Wolfram, Josef Poulík and István Bóna) rejected his argument, but other scholars, including Charles Bowlus and Martin Eggers, developed them further in the 1990s. According to Florin Curta, who does not support the alternative theories, Bowlus has written the "most elegant presentation" of their argumentation. Scholars who support the traditional boundaries argue that no archaeological evidence substantiates the existence of a 9th-century power center in the lands where the alternative theories suggest Moravia's core region would have been. On the other hand, excavations proved that important centers of power existed at Mikulčice, Pohansko and other settlements north of the Middle Danube in the as it was predicted by the traditional view.
Michael McCornick says that Boba and his followers generated a "healthy debate". Curta emphasizes that the location of Moravia "may be understandably viewed as a matter of nationalist concern", because of "a quite recent history of shifting political frontiers" in Central Europe. He also writes that "a hostile, rather than critical, attitude towards Boba's ideas became the norm among Slovak historians" in the early 1990s. Vincent Sedlák, a Slovak historian, argues that Boba developed his theory "to deny the historical validity of Slovak territory"; Curta writes that this is not a baseless statement. Most arguments of Boba and his followers have been "effectively countered", but the "interpretation of the written evidence provided by the Frankish sources continues to be debated", according to Nora Berend, Przemyslaw Urbańczyk and Przemyslaw Wiszewski. Jiří Macháček, also an opponent to the alternative theories, argues that "the serious problems of geographical orientation raised by analysis of the written sources, which ultimately led Imre Boba and his followers to question the traditional location of Great Moravia, will have to be explained in some other way." However, he also says, the alternative theories have been demonstrated to be a non-perspective branch of research and they are not accepted by the international scientific community.Macháček associates rejection of these theories by the scientific community with their poor quality. Macháček as a director of research laboratory of the Masaryk University at Břeclav-Pohansko notices also regular participation of international teams on archeological research, in the last years mainly experts from USA, Germany and Austria. According to Roger Collins, the dispute about Moravia's location "remains to be resolved"; he also argues that archaeological evidence should not be overemphasized against written sources.
Southern Moravia of Juraj Sklenár
In 1784, Juraj Sklenár, a Slovak historian and teacher of rhetoric in Pozsony/Pressburg (today's Bratislava), published Vetustissumus magnae Moravie situs et primus in eam Hungarorum ingressus et incursus (). His work had a political purpose and character. He argued that the Magyars never conquered the territory inhabited by the Slovaks and the latter voluntarily joined the Kingdom of Hungary during the rule of Ladislaus I of Hungary.