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
Commissions of the Danube River effective control of the Lower Danube in May 1939, when the Sinaia Agreement (concluded on 18 August 1938) entered into force. "See main articles Nazi rule over the Danube River (1938–1945) and Danube Commission (after 1945)" In 1938, a committee of experts inspected the Sulina and found it was almost impassable by that time. And in August of that same year, the regime of the two commissions was swept away by rise of German power on the river. A series of treaties put control in the hands of the Germans, who maintained it until the Nazi retreat in 1944 and