Polish Army Occupied Kiev: The Kiev Offensive was an attempt by the armed forces of the newly re-emerged Poland led by Józef Piłsudski, in alliance with the Ukrainian leader Symon Petliura, to seize the territories of modern-day Ukraine which fell under the Soviet control after the Bolshevik Revolution. The initial expedition in which 65,000 Polish and 15,000 Ukrainian soldiers took part, started on April 24, 1920. The military goal was to outflank the Soviet forces and destroy them in a single battle. After winning the battle in the South, the Polish General Staff planned a rapid withdrawal of the 3rd Army and strengthening of the northern front where Piłsudski expected the main battle with the Red Army to take place. The Polish southern flank was to be held by Polish-allied Ukrainian forces under a friendly government in Ukraine. On May 7, Polish and Ukrainian soldiers entered Kiev.
A general meeting of Camp of National Unity took place in Katowice. It was a Polish political party founded in 1937 by some members of the Sanacja leadership whose platform was strongly pro-military. Its objectives were to improve Poland's national defense and to safeguard the April 1935 Constitution. Its politicians claimed that Marshal Rydz-Śmigły as "the second person in the country" after President Moscicki, which had no foundation in the Constitution.
The Battle of Halbe began on the Eastern Front. In this battle, the German Ninth Army, under the command of General Theodor Busse, was destroyed as a fighting force by the Red Army during the Battle for Berlin. After heavy fighting, the Battle ended on May 1, 1945. About 30,000 German soldiers—one fifth of those originally in the pocket—reached the comparative safety of the Twelfth Army's front lines. The rest were either killed or captured by the Soviet forces.
German submarine U-546 was responsible for the last combat sinking of a United States Navy vessel in the Atlantic, the destroyer escort USS Frederick C. Davis. Immediately, five US destroyers turned on the U-boat, assisted by other destroyer escorts; Flaherty (DE-135) (LCDR H.C. Dufe), Varian (DE-798) (LCDR L.A. Myhre), Neunzer (DE-150) (LCDR V.E. Gex), Hubbard (DE-211) (CDR L.C. Mabley), Keith (DE-241) (LCDR W.W. Patrick), Chatelain (DE-149) (LCDR D.S. Knox), Janssen (DE-396) (LCDR S.G. Rubinow, Jr.), and Pillsbury (DE-133) (LCDR G.W. Casselman). Neunzer and Hayter (DE-212) conducted a search while Pillsbury circled the area and Flaherty picked up survivors. Flaherty made spotted the U-boat in less than an hour and with Pillsbury proceeded to attack. The U-boat dove to 600 feet (180 m). Contact was lost from 1045 until 1201 when Varian, Janssen and Hubbard began another attack. Neunzer got into the fight after several attacks by the other DE's, delivering a creeping attack with Varian and Hubbard while Chatelain directed. Contact was lost once more at about 1600, so Chatelain and Neunzer were ordered to return to the scouting line. Varian made contact once more at 1731 and Flaherty was ordered to attack. She fired at 18:10. Four minutes later a small oil slick appeared on the surface.. Flaherty made another Hedgehog attack at 1828, and at 1838 the U-boat broke the surface. Every US destroyer lined up and began firing at the German sub. After more than ten and a half hours of battle, at 1844, the U-546 rolled under and sank (in position 43°53′N 40°07′W, south-south-east of Cape Farewell, Greenland). The subs captains and crew were rescued by US vessels and detained at the Argentia Naval Station in Newfoundland, Canada, where they were tortured by US military personnel. The Allies needed to obtain information on potential cruise missiles or ballistic missile attacks on the U.S. continent. The USN eventually learned that no V-1/2 attacks from the U-boats were planned by the Kriegsmarine.