Danube name meaning "strong, swift" (akin to Sanskrit "iṣiras" "swift"). In Latin, the Danube was variously known as ' or as '. The Dacian/Thracian name was "Donaris" for the upper Danube and "Istros" for the lower Danube. The Thraco-Phrygian name was "Matoas", "the bringer of luck". The Latin name is masculine, as are all its Slavic names, except Slovenian, (the name of the Rhine is also masculine in Latin, most of the Slavic languages, as well as in German). The German "Donau" (Early Modern German "Donaw, Tonaw", Middle High German "Tuonowe") is feminine, as it has been re-interpreted as containing the
Danube of Vienna during the times of the Austro-Hungarian Empire. Since ancient Roman times, famous emperors and their retinue travelled on and along the Danube and used the river for travel and transportation. While travelling on the mainland was quite exhausting, most people preferred to travel by ship on the Danube. So the Route of Emperors and Kings was the setting for many important historical events, which characterize the Danube up until today. The route got its name from the Holy Roman Emperor Frederick I of Barbarossa and the crusaders as well as from Richard I of England who had been