Admiral Soemu Toyoda is appointed commander-in-chief of the Japanese Combined Fleet. He replaces Admiral Mineichi Koga, who has been killed in a plane crash on March 31.
Eastern Front, Crimea
The Soviet 4th Ukrainian Front liberates the port of Sebastopol. It is a crushing defeat for the German defenders, who have lost 100,000 men killed and captured during the fighting.
The Allied 15th Army Group begins its offensive to outflank the monastery. On the 12th, the French Expeditionary Corps takes Monte Faito, but the Polish 5th Division fails to capture Colle Sant’Angelo. On the 13th, the French open the way to Rome, while the US II Corps takes Santa Maria Infante, and the British 4th Division begins to enlarge its bridgehead across the Rapido River.
On the 17th, the Germans evacuate the monastery at Monte Cassino because of the deep breakthroughs by the French Expeditionary Corps and the US II Corps. The next day, the Polish 12th Podolski Regiment storms the ruins of Monte Cassino.
The last pockets of Japanese resistance on the islands have been crushed. This effectively isolates the main Japanese bases at Rabaul and Kavieng in the southwest Pacific.
Home Front, Germany
Following their recapture after a mass breakout from Stalag Luft III near Sagan, Silesia, 50 Allied airmen are shot by the Gestapo. Only three of the escaped prisoners - two Norwegians and a Dutchman - reach England.
Troops of the US VI Corps begin the breakout from the Anzio beachhead in the face of stubborn German resistance. The linkup with troops of the US II Corps occurs on the 25th, four months after the original Anzio landing. Steady gains are made by the Allies, although taking the Adolf Hitler Line, which runs from Terracina on the coast along the Foni to Pico road to Pontecorvo and across the Liri Valley through Aquino and Piedmonte to Monte Cairo, does result in heavy Allied losses. Once again the Germans have proved adept at defense.
On the 25th, the US Fifth Army attacks toward Rome, but is held by the Germans, who have had time to dig in around Valmontone along the Caesar Line. It is not until the night of May 30 - when Major General Fred L. Walker’s US 36th Division moves silently up Monte Artemisio and breaks the Valmontone defenses - that the final defensive line barring the entrance to Rome is cut.
The Germans launch an air, glider, and mortar attack on the partisan headquarters at Divar, in which Marshal Tito narrowly escapes capture. The attack is believed to have been the plan of SS Major Otto Skorzeny, the officer who rescued Mussolini.
Pacific, Papua New Guinea
The first tank battle of the Pacific campaign is fought on Biak Island, off New Guinea, between the Japanese and Americans. It is a US victory.