Bohemia ( boh-HEE-mee-ə; Czech: Čechy [ˈtʃɛxɪ] ; German: Böhmen [ˈbøːmən] ) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohemian kings, including Moravia and Czech Silesia, in which case the term refers to the historical cultural and political space of the Czech people. The smaller region is then referred to as Bohemia proper as a means of distinction.
The 9th century Bohemian principality became a part of Great Moravia, and then an independent Duchy of Bohemia, which became a kingdom in the Holy Roman Empire. This subsequently became a part of the Habsburg monarchy and the Austrian Empire. After World War I and the establishment of an independent Czechoslovak state, the whole of Bohemia became a part of Czechoslovakia, defying claims of the German-speaking inhabitants that regions with German-speaking majority should be included in the Republic of German-Austria. Between 1938 and 1945, these border regions were annexed to Nazi Germany as the Sudetenland.
The remainder of Czech territory became the Second Czechoslovak Republic and was subsequently occupied as the Protectorate of Bohemia and Moravia until the end of World War II, after which Bohemia became part of the restored Czechoslovakia. In 1968, the Czech lands (including Bohemia) were invaded by Warsaw Pact troops sent by the Soviet Union and stayed under occupation as the Czech Socialist Republic until the Velvet Revolution in 1989. In 1990, the name was changed to the Czech Republic, which became a separate state in 1993 with the breakup of Czechoslovakia.
Until 1948, Bohemia was an administrative unit of Czechoslovakia as one of its "lands" (země). Since then, administrative reforms have replaced self-governing lands with a modified system of "regions" (kraje), which do not follow the borders of the historical Czech lands (or the regions from the 1960 and 2000 reforms). However, the three lands are mentioned in the preamble of the Constitution of the Czech Republic: "We, citizens of the Czech Republic in Bohemia, Moravia and Silesia..."
Bohemia had an area of 52,065 km2 (20,102 sq mi), and today is home to about 6.9 million of the Czech Republic's 10.9 million inhabitants. Bohemia was bordered in the south by Upper and Lower Austria (both in Austria), in the west by Bavaria (in Germany), and in the north by Saxony and Lusatia (in Germany and Poland, respectively), in the northeast by Silesia (in Poland), and in the east by Moravia (also part of the Czech Republic). Bohemia's borders were mostly marked by mountain ranges such as the Bohemian Forest, the Ore Mountains, and the Giant Mountains; the Bohemian-Moravian border roughly follows the Elbe-Danube watershed.
In the second century BC, the Romans competed for dominance in northern Italy with various peoples, including the Gauls-Celtic tribe Boii. The Romans defeated the Boii at the Battle of Placentia (194 BC) and the Battle of Mutina (193 BC). Afterward, many of the Boii retreated north across the Alps. Much later Roman authors refer to the area they had once occupied as Boiohaemum. The earliest mention is in Tacitus' Germania 28 (written at the end of the first century AD), and later mentions of the same name are in Strabo and Velleius Paterculus. The name appears to consist of the tribal name Boio- plus the Proto-Germanic noun *haimaz "home" (whence Gothic haims, German Heim, Heimat, English home), indicating a Proto-Germanic *Bajahaimaz.
Boiohaemum was apparently isolated to the area where King Marobod's kingdom was centered, within the Hercynian Forest. Byzantine Emperor Constantine VII in his 10th-century work De Administrando Imperio also mentioned the region as Boiki (see White Serbia).
The Czech name "Čechy" is derived from the name of the Slavic ethnic group, the Czechs, who settled in the area during the sixth or seventh century AD.
Bohemia, like neighboring Bavaria, is named after the Boii, a large Celtic nation known to the Romans for their migrations and settlement in northern Italy and other places. Another part of the nation moved west with the Helvetii into southern France, one of the events leading to the interventions of Julius Caesar's Gaulish campaign of 58 BC. The emigration of the Helvetii and Boii left southern Germany and Bohemia a lightly inhabited "desert" into which Suebic peoples arrived, speaking Germanic languages, and became dominant over remaining Celtic groups. To the south, over the Danube, the Romans extended their empire, and to the southeast, in present-day Hungary, were Dacian peoples.
In the area of modern Bohemia, the Marcomanni and other Suebic groups were led by their king, Marobodus, after being defeated by Roman forces in Germany. He took advantage of the natural defenses provided by its mountains and forests. They were able to maintain a strong alliance with neighboring tribes, including (at different times) the Lugii, Quadi, Hermunduri, Semnones, and Buri, which was sometimes partly controlled by the Roman Empire and sometimes in conflict with it; for example, in the second century, they fought Marcus Aurelius.
In late classical times and the early Middle Ages, two new Suebic groupings appeared west of Bohemia in southern Germany, the Alemanni (in the Helvetian desert) and the Bavarians (Baiuvarii). Many Suebic tribes from the Bohemian region took part in such movements westward, settling as far away as Spain and Portugal. With them were also tribes who had pushed from the east, such as the Vandals and Alans.
Other groups pushed southward toward Pannonia. The last known mention of the Kingdom of the Marcomanni, concerning a queen named Fritigil, is from the fourth century, and she was thought to have lived in or near Pannonia. The Suebian Langobardi, who moved over many generations from the Baltic Sea, via the Elbe and Pannonia to Italy, recorded in a tribal history a time spent in "Bainaib".
After the Migration Period, Bohemia was partially repopulated around the sixth century, and eventually Slavic tribes arrived from the east, and their language began to replace the older Germanic, Celtic, and Sarmatian ones. These are precursors of today's Czechs, but the exact amount of Slavic immigration and waves is a subject of debate, see Bohemians (tribe). The death of Samo's tribal confederation marked the end of the old "Slavonic" confederation, the second attempt to establish such a Slavonic union after Carantania in Carinthia.
The 9th century was crucial for Bohemia's future. The manorial system sharply declined, as it did in Bavaria. The influence of the central Fraganeo-Czechs grew, as a result of the important cultic center in their territory. They were Slavic-speaking and contributed to the transformation of diverse neighboring populations into a new nation named and led by them with a united "Slavic" ethnic consciousness. Christianity first appeared in the early 9th century, but became dominant only in the 10th or 11th century.
Bohemia was made a part of the early Slavic state of Great Moravia, under the rule of Svatopluk I (r. 870–894). After Svatopluk's death Great Moravia was weakened by years of internal conflict and constant warfare, ultimately collapsing and fragmenting because of continual incursions by invading nomadic Magyars. Bohemia's initial incorporation into the Moravian Empire resulted in the extensive Christianization of the population. A native monarchy arose, and Bohemia came under the rule of the Přemyslid dynasty, which ruled the Czech lands for several hundred years.
The Přemyslids secured their frontiers after the Moravian state's collapse by entering into a state of semivassalage to the Frankish rulers. The alliance was facilitated by Bohemia's conversion to Christianity in the 9th century. Continuing close relations were developed with the East Frankish Kingdom, which devolved from the Carolingian Empire, into East Francia, eventually becoming the Holy Roman Empire.