in the tenth century with its founding by Liudolf, Duke of Swabia, as a stud farm for his warhorses. Initially overshadowed by nearby Bad Cannstatt, the town grew steadily and was granted a charter in 1320. The fortunes of Stuttgart turned with those of the House of Württemberg, and they made it the capital of their county, duchy, and kingdom from the 15th century to 1918. Stuttgart prospered despite setbacks in the Thirty Years' War and devastating air raids by the Allies on the city and its automobile production during World War II. However, by 1952, the city had bounced back and became the major economic, industrial, tourism and publishing centre it is today. Stuttgart is known for its strong high-tech industry, especially in the automotive sector. It has the highest general standard of prosperity of any German city. In addition to many medium-sized companies, several major corporations are headquartered in Stuttgart, including Porsche, Bosch, and Mercedes-Benz Group. Stuttgart is an important financial center; the Stuttgart Stock Exchange is the second largest in Germany (after Frankfurt), and the Landesbank Baden-Württemberg (LBBW) is Germany's largest Landesbank. Stuttgart is also a major transport junction; it is among the most congested conurbations of Europe, and its airport is the sixth-busiest in Germany (2019). Stuttgart is a city with a high number of immigrants; according to Dorling Kindersley's Eyewitness Travel Guide to Germany, "In the city of Stuttgart, every third inhabitant is a foreigner." 40% of Stuttgart's residents, and 64% of the population below the age of five, are of immigrant background. Etymology Stuttgart, often nicknamed the "Schwabenmetropole" () in reference to its location in the centre of Swabia and the local dialect spoken by the native Swabians, has its etymological roots in the Old High German word Stuotgarten, or "stud farm", because the city was founded in 950 AD by Duke Liudolf of Swabia to breed warhorses. In the local dialects of Alemannic German it can be "Schtuegert", and in Swabian German "Stuagart"; with similar variant spellings, usually dropping the central T sound. History Antiquity Originally, the most important location in the Neckar river valley was the hilly rim of the Stuttgart basin at what is today Bad Cannstatt. Thus, the first settlement of Stuttgart was a massive Roman Castra stativa (Cannstatt Castrum) built AD to protect the Villas and vineyards blanketing the landscape and the road from Mogontiacum (Mainz) to Augusta Vindelicorum