and Baranya. They comprised the so called Districtus Trans-Danubianus from the beginnings of the 18th century. The boundaries of these counties, established by Stephen I of Hungary remained unchanged for almost 900 years until 1920. Ancient history Transdanubia has been populated since the Stone Age. Between 10 BCE and 434 CE, it was part of the Roman Empire. With some present-day Austrian and Croatian territories, it comprised the Province of Pannonia, a romanised, Latin-speaking border region with important Roman towns (Scarbantia, Aquincum, Sopianae, Gorsium, Savaria) and rural villas. Middle Ages In the Age of Migrations it was occupied by the Huns, Ostrogoths, Lombards, Gepids, Avars, Franks and the Slavic peoples. In 900 Pannonia was occupied by the Magyars and after 1000 became part of the Kingdom of Hungary. 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. Early modern times In the Ottoman era (16-17th centuries) the eastern and southern part of Transdanubia came under Turkish rule. The ever changing border ran along the Transdanubian Mountains and the southern shore of the Lake Balaton. The dangerous border was guarded by frontier-fortresses (végvár), the most important of which were Győr and Nagykanizsa. The Asian-style Ottoman rule and the constant war had devastating effects: dozens of villages were destroyed, the population was decimated and parts of the region became almost totally deserted. The territories belonging to the Royal Hungary (except the border regions) were more lucky, because the European-like developments were continuous. Here the 17th century was the period of the Catholic Counter-reformation, the fights for national independence from the Habsburgs and the formation of a new, powerful Catholic aristocracy. 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 many new settlers (Magyars, Germans, Poles, Slovaks,