The US Third Fleet under Admiral William Halsey was protecting the landings of Allied forces at Leyte in the Phillipines. The Japanese plan was to lure the Third Fleet away to the North using an aparrently vulnerable force of aircraft carriers, and then to attack the landing forces with two attack forces sailing from the West. The diversion was successful, yet one of the Japanese attack forces was driven off by a force of six old battleships, five raised from the bottom of Pearl Harbour.
The other attack force fell on a group of escort carriers, designed for anti-submarine warfare, and escorting destroyers. Massively outgunned the carriers fought back, and the Japanse withdrew. Meanwhile Halsey's carriers had inflicted heavy damage on the decoy force. Four carriers were destroyed. When added to the three battleships and nineteen smaller ships it represented a quarter of the Japanese losses so far.
Having defended the landing force against the air and naval challenge, the way was opened for the reconquest of Leyte by the land forces under the command of General Douglas MacArthur, in the Battle of Leyte.