See Gerald Stone,
The Smallest Slavonic Nation: The Sorbs of Lusatia:
"In the early years of Nazi power the official policy towards the Sorbs did not alter as much as might have been expected. The aim was to play down the 'Wendish question' and to accelerate germanization as quietly as possible. From 1935 another German organization concerned with the germanization of the Sorbs and other Slavs began to make its presence felt. This was the
Bund Deutscher Osten, led by Professor T. Oberlander, who was later to achieve further distinction as a minister in Dr. Adenauer's West German Cabinet. Hitler had given instructions that the
Bund Deutscher Osten (BDO) should extend its activities to Saxony and deal with the 'Wendish question'. To begin with there appears to have been a demarcation dispute as to the respective duties of the BDO and the
Wendenabteilung, but having got over this difficulty they proceeded to work in harmony.
"One by one the Sorbian national organizations were closed down. The Sokol was forced to disband in 1933. The Lusatian Peasants' Union was banned in the same year. In 1937 the
Domowina was closed down and virtually all Sorbian publications were forbidden. The only exceptions were Catholic publications of exclusively religious content, which were protected by the Nazi Concordat with the Vatican. These too, however, were closed down on the outbreak of war in 1939. The dissolution of the
Domowina was accompanied by widespread confiscation of Sorbian property, including the library of the
Modica Serbska and the exhibits in its museum. Literature to a value of over 100,000 marks was destroyed. The thirties also saw the arrest of many Sorbian intellectuals and public figures. Some were subsequently released, only to be rearrested later. Others were taken to concentration camps, sometimes never to return.
"With the outbreak of war in 1939 many Sorbs once again found themselves in the German army. Those that were able to remain at home in Lusatia lived in constant fear of deportation, and it clearly would have been a relatively simple matter for the German authorities to disperse the entire population. There were certainly plans to deport all Sorbs, but before these plans could be finalized and put into effect the change of German fortunes at Stalingrad distracted all attention from this relatively minor problem. Immediately after the outbreak of war the Germans began to bring into Lusatia large numbers of prisoners of war and forced labourers from Poland and Russia. The Sorbs naturally found that they had much in common with these people, first of all simply on the linguistic plane, particularly with the Poles. More significant, though, was their sense of solidarity with other victims of Nazi oppression. It was for these reasons, and often simply on humanitarian grounds, that the Sorbs gave help to these unfortunates. In many cases the Sorbs enabled them to escape and then kept them hidden until the arrival of the Soviet forces in 1945."
https://books.google.com/books?id=sH5qCgAAQBAJ&pg=PA35