Short answers, pulled from the story.
The German geographer Oscar Peschel used a specific phrase in 1860 to describe how physical geography influences human activity. Friedrich Ratzel published a book applying this concept by 1897 and extended his thesis into an essay titled Lebensraum: A Biogeographical Study in 1901.
Adolf Hitler stated that conquest of living space in Eastern Europe was an ultimate geopolitical objective on the 3rd of February 1933 during his initial meeting with generals and admirals. He dedicated a full chapter titled Eastern Orientation or Eastern Policy to outlining this need in 1925.
Himmler commissioned drafting of Generalplan Ost on the 21st of June 1941 which became the blueprint for German expansionist and extermination policies in Eastern Europe. The program launched genocide of millions of Slavs, Jews, and Romani people through mass-killings, forced starvations, and extermination through slave labour.
The treaty transferred 33% of arable land, 30% of industry, and 90% of coal mines of Russia to Germany when Bolshevik Russia agreed to territorial cessions in March 1918. This extensive geopolitical victory was abandoned due to tactical defeat on the Western Front before Imperial Germany could realize these plans.
Nazis forcibly removed some 50,000 ethnic Poles from Polish territories annexed to Greater German Reich during four years of Germanisation from 1940 to 1944. Specific cases like Action Saybusch affected 18,000 to 20,000 ethnic Poles from Żywiec County in Polish Silesia as part of the Polish Campaign.