How have Germany's borders changed from 1919 - 1990 and why?

In 1919, Germany lost a number of small portions of land: to Poland, France and Denmark

-during the WW2, Germany annexed a lot of land, including Chechia and parts of Poland

-after the war, a big part of Eastern Germany was given to Poland, and Germany was split into Western and Eastern Germany

-in 1990 it was reunited and the borders have been stable ever since