Latvia states of Northern and Eastern Europe were divided into German and Soviet "spheres of influence". In the north, Latvia, Finland and Estonia were assigned to the Soviet sphere. A week later, on 1 September 1939, Germany and on 17 September, the Soviet Union invaded Poland. After the conclusion of the Molotov-Ribbentrop Pact, most of the Baltic Germans left Latvia by agreement between Ulmanis' government and Nazi Germany under the Heim ins Reich programme. In total 50,000 Baltic Germans left by the deadline of December 1939, with 1,600 remaining to conclude business and 13,000 choosing to remain in Latvia. Most of
Germany–Poland border German reunification, the border became part of the eastern border of the European Community, then that of the European Union. For a period, it was "the most heavily policed border in Europe". After Poland joined the European Union in 2004, the border controls were relaxed in agreement with the Schengen Agreement to eliminate passport controls by 2007. The modern borderlands of Poland and Germany are inhabited by about one million of those countries' citizens within the counties on each side. Germany–Poland border The Germany–Poland border (, ), the state border between Poland and Germany, is currently the Oder–Neisse line. It