The group of settlers commonly referred to as "Germans from Odessa and the Black Sea" were immigrants from western and southern Germany (followed later by Prussian Mennonites and Swabians) who settled on the northern coast of the Black Sea between Odessa and the Caucasus. They followed the invitations extended by Catherine the Great and Tsar Alexander I. to colonize large areas of Russia.
History [1]
The history of the Black Sea Germans is more than 200 years old. At the end of the 18th century, Russia conquered in the war against the Turks vast areas of the steppe by the Black Sea, the cultivation of which was to be implemented immediately. As serfdom limited the Russian peasants in their freedom of movement and thus made an immediate settlement of the new area impossible, foreign settlers were recruited. In July 1763, Tsarina Catherine II. issued in a manifesto the permit to all foreigners coming to Russia to settle in gouvernements of their choice and granted them special rights. The Tsarina's manifesto also guaranteed foreign settlers the right of free religion and self-government aside from various economic and political privileges. Her call was most welcome in the German small states where economic hardship, denominational differences, and wars had suppressed the population.
German national districts in Ukraine
During World War II the fate of the Black Sea Germans was determined by the swift occupation of the Black Sea region by Rumanian and German troops. While the Germans living east of the Dnjepr river were deported to Siberia, the Germans living west of the Dnjepr were initially under the protection of the German Reich. They were registered in the so-called "List of German people" which later on served as the basis for handing out German certificates of naturalization. By the end of 1943 the resettlement of Black Sea Germans from the occupied areas to the Warthe-Gau began.
Those who survived the travails of the flight were settled on farmsteads of expelled Polish people in order to "Germanize" the region. But the advance of the Red Army soon forced the settlers to continue to fleeing westward. After the war, a large number of the Germans from the Black Sea region who had come to the western occupied zones of Germany managed to go into hiding in order to escape extradition to Soviet occupation forces and repatriation to the Soviet Union. Others were allowed to travel on to America. However, a large number of Black Sea Germans were handed over to Soviet commando units and were deported to Siberian special camps and labor camps, suffering huge losses in the process.
https://sites.ualberta.ca/~german/AlbertaHistory/Odessa.htm