From Wikipedia

The Last Days of World War II - Death of the Reich

On December 16, 1944, Germany attempted its last desperate measure for success by marshaling German reserves to launch a massive counteroffensive in the Ardennes to attempt to split the Western Allies, encircle large portions of Western Allied troops and capture their primary supply port at Antwerp in order to prompt a political settlement. The offensive was spearheaded by Germany's top army group and over one million total soldiers fought in the battles. The offensive had been repulsed by January with no strategic objectives fulfilled. The Soviets attacked through Hungary, while the Germans abandoned Greece and Albania, and were driven out of southern Yugoslavia by partisans. In Italy, the Western Allies remained stalemated at the German defensive line. In mid-January 1945, the Soviets attacked in Poland, pushing from the Vistula to the Oder river in Germany, and overran East Prussia.

On February 4, U.S., British, and Soviet leaders met in Yalta. They agreed on the occupation of post-war Germany, and when the Soviet Union would join the war against Japan.

American and Soviet troops meet east of the Elbe River.

In February, the Soviets invaded Silesia and Pomerania, while Western Allied forces entered western Germany and closed to the Rhine river. In March, the Western Allies crossed the Rhine north and south of the Ruhr, encircling a large number of German troops, while the Soviets advanced to Vienna. In early April the Western Allies finally pushed forward in Italy and swept across western Germany, while in late April Soviet forces stormed Berlin; the two forces linked up on Elbe river on April 25.