yes

WW1 It's not an area that I studied very closely or know too much about...however surely the most dramatic migration was that forced by Eastern European and particularly German based Jews who fled during WW2. They ended up far and wide in the world...many children were brought to the UK. However there were many strands to migration during and post WW2 as the Germans had encouraged it's citizens to populate their newly conquered territories. These peoples had to flee their new homes and land after the war ended

This comes from the BBC's website Post-war scramble The end of World War Two brought in its wake the largest population movements in European history. Millions of Germans fled or were expelled from eastern Europe. Hundreds of thousands of Jews, survivors of the genocide perpetrated by the Nazis, sought secure homes beyond their native lands. And other refugees from every country in eastern Europe rushed to escape from the newly installed Communist regimes.

The expulsions were ... conducted in a ruthless and often brutal manner.

At the Potsdam Conference in July 1945, British, American and Russian leaders agreed to '... recognise that the transfer to Germany of German populations ... remaining in Poland, Czechoslovakia and Hungary, will have to be undertaken.' They also specified that '... any transfers that take place should be effected in an orderly and humane manner.' The expulsions were, in fact, conducted in a ruthless and often brutal manner.

And did it change in 20th century compared to the 19th century? Interesting questions...