Transdanubia (Dunántúl; Transdanubien) is a traditional region of Hungary.
Transdanubia comprises the counties of Győr-Moson-Sopron, Komárom-Esztergom, Fejér, Veszprém, Vas, Zala, Somogy, Tolna, Baranya and the part of Pest that lies west of the Danube. (In the early Middle Ages the latter was known as Pilis county.)
This article deals with Transdanubia in this geographical meaning.
While the northern, eastern and southern borders of the region are clearly marked by the Danube and Drava rivers, the western border was always identical with the political boundary of Hungary, therefore it was affected by the territorial changes of the 20th century. Before the Treaty of Trianon in 1920 the present-day regions of Burgenland, Prekmurje and Međimurje were integral parts of Transdanubia. The three villages of Rusovce, Čunovo and Jarovce also belonged to Transdanubia before the Paris Peace Treaty in 1947. Transdanubia is essentially a Hungarian geographical concept so these areas ceased to be parts of it when they were annexed by neighbouring countries.
Transdanubia has been one of the most important regions of Hungary since the 11th century. Esztergom has been the ecclesiastical capital of the country since 1001 until today, and Stephen I of Hungary established his royal seat at Székesfehérvár, later the coronation town of the kings. Other important medieval cities were Veszprém, Pécs, Győr and Sopron. After the devastating Mongol invasion (see Mongol invasion of Europe) new castles were built, and King Béla IV of Hungary established a new royal capital at Buda, next to the Danube. The region's rich medieval heritage is seen everywhere from the little village churches to the old castles, monasteries and town houses.
In 1686 the allied Habsburg, Polish and Bavarian army reconquered Buda and terminated the Ottoman rule. In the 18th century the region was slowly rebuilt, and lots of new settlers (Magyars, Germans, Slovaks, Croatians) arrived. Famous baroque castles were built to show the power of the big landowner families, for example the Esterházys in Fertőd and the Festetichs in Keszthely. The baroque townscape of the cities survived until today in Győr, Székesfehérvár, Pécs etc.
In the 19th century Trandanubia underwent a capitalist development. Thanks to the closeness of Austria it became again the richest part of the country, and – at least after the public opinion – more "European" and Western-like than any other region of Hungary or most regions of post-communist Central Europe.
Under the Socialism (1949-1989) new industrial cities were built at Tatabánya, Dunaújváros, Ajka and Komló, and new industries and factories were established, for example Hungary's only atomic power plant at Paks. In Pécs uranium was mined and big industrial suburbs were built. One of the most famous plant of Socialist Hungary, the Ikarus Bus was established in Székesfehérvár. After the fall of Socialism, northern Transdanubia was more successful at adapting to the new economical situation than other parts of Hungary (except Budapest) and most of the foreign investment came here to help the radical economical renewal. In the 1990s Székesfehérvár was counted as probably the economically most successful Hungarian town. On the other hand some rural regions remained impoverished, especially in Southern Transdanubia and along the River Drave.