On 23 October, the Battle of Leyte Gulf began. Almost the entirety of Japan's remaining surface fleet had been concentrated into a counterattack against the U.S. forces in the vicinity of the Philippines, which had threatened to cut off Japan's vital oil supply from Southeast Asia. Split into three groups, the Southern Force was defeated in the Battle of Surigao Strait, whilst Vice Admiral William Halsey Jr. sent the Third Fleet in an attack against the diversionary Northern Force. Therefore, the escort carriers which continued providing ground support had no capital ship screening, even as Vice Admiral Takeo Kurita's Center Force drove through the San Bernardino Strait during the night. On the early morning of 25 October, the Center Force emerged into the waters of the Leyte Gulf, catching Taffy 3, some north of "Savo Island", by surprise.