Walachia or Wallachia (both: wälā´kēə, wə–), historic region (29,568 sq mi/76,581 sq km), S Romania. The Transylvanian Alps separate it in the NW from Transylvania and the Banat; the Danube separates it from Serbia in the west, Bulgaria in the south, and N Dobruja in the east; in the northeast it adjoins Moldavia. Bucharest, the Romanian capital, is its chief city. The Oltul River, a tributary of the Danube, divides Walachia into Muntenia or Greater Walachia (20,265 sq mi/52,486 sq km) in the east and Oltenia or Lesser Walachia (9,303 sq mi/24,095 sq km) in the west.
With the rich Ploieşti oil fields and the industrialized area near Bucharest, Walachia is economically the most developed region of Romania. Its industries (notably chemicals, heavy machinery, and shipbuilding) provide employment for about half of the country's labor force. Walachia is also a rich agricultural area and the "breadbasket" of Romania. The overwhelming majority of the population is Romanian, but there are also Bulgarians and Serbs. The pre–World War II Jewish population of about 600,000 was reduced to about 18,000 by 1990, with the numbers still declining.
The region was part of the Roman province of Dacia and has retained its latinate speech despite centuries of invasion and foreign rule. Although theoretically part of the Byzantine Empire, Walachia was successively occupied (6th–11th cent.) by the Lombards, the Avars, and the Bulgarians. By the 12th cent. it had passed under the Cumans, who in turn succumbed (1240) to the Mongols.
When the Mongol wave receded, the native inhabitants descended from their mountain refuges, and the principality of Walachia was founded (c.1290) by their leader Radu Negru, or Rudolf the Black. The name Vlachs (or Walachs or Wallachs) was given them by their Slavic neighbors. Although some claim that the Vlachs are direct descendants of the Dacians (mainly on the ground that they preserved their Latin speech), it is more than likely that they represent a composite ethnic mixture. The sister principality, Moldavia, came into existence about the same time as Walachia. Cîmpulung, the earliest capital of Walachia, was later replaced by Curtea de Arges.
Mircea the Great of Walachia (reigned 1386–1418) shared in the defeats of Kosovo Field (1389) and Nikopol (1396) at the hands of the Turks and was obliged to pay tribute to the sultan. Walachia continued to be governed by its own princes under Turkish suzerainty. Like Moldavia, it was torn by strife among the great landowners (or boyars) and among rival claimants to the throne; lawlessness prevailed. Prince Vlad the Impaler (reigned 1456–62) restored some order by putting 20,000 persons to death within six years. He refused tribute to the sultan, defeated the Turks, and impaled the Turkish prisoners. His rivalry with Stephen the Great of Moldavia cost him his throne. A last attempt to free all Romanians from foreign domination was made (1593–1601) by Michael the Brave, who massacred the Turks in Walachia and conquered Transylvania and Moldavia. His death delivered Walachia back into the hands of the Turks.
The alliance (1711) of Prince Constantine Brancovan with Peter I of Russia and his subsequent downfall resulted in a tightening of Turkish control. Instead of native princes, governors (hospodars), mostly Greek Phanariots (see under Phanar), were appointed. In the Russo-Turkish Wars of the 18th cent. Walachia was repeatedly occupied by Russian and Austrian troops. The oppressive rule of the Phanariots lasted until 1822, when the Romanians rebelled against the Greeks, who at the same time began their war of independence against Turkey.
Native governors were again appointed, and the Treaty of Adrianople (see Adrianople, Treaty of) in 1829 made Walachia an almost autonomous state, tributary to Turkey but under Russian protection. A Romanian national uprising (1848–49) in Walachia was suppressed by Russian intervention. Russian troops occupied (1853) Walachia and Moldavia early in the Crimean War; however, to purchase Austrian neutrality, they evacuated the lands in 1854, and the two Danubian Principalities (as Walachia and Moldavia were called) passed under Austrian occupation. The Congress of Paris (1856), which ended the Crimean War, guaranteed the principalities virtual independence under the nominal suzerainty of Turkey. With the accession (1859) of Alexander John Cuza as prince of both Moldavia and Walachia, the history of modern Romania began.