The Second World War in the Pacific started on 7th December 1941, by surprise, by attack on the American naval base at Pearl Harbor. It was a time when the Combined Fleet under Admiral Isoroku Yamamoto had obtained  significant tactical and strategic successes. In the battle of Midway in June 1942 Japan lost four aircraft carriers. The defeated Combined Fleet returned to their home base, losing a large part of their military potential. Japanese  military potential was intensively reduced after the battle of Midway. This was a turning point in the war in the Pacific that determined the war’s further course. Japan was not able to stop their enemy who has been growing in strength  and with each passing day was better equipped. In 1943, when Admiral Mineichi Koga was appointed as commander in chief of the Combined Fleet, Japanese aircraft carriers remained in their main bases and haven’t been involved  n any advanced combat activity. This situation changed on June 1944, when the United States began a major offensive on the Mariana Islands. It was the next turning point in the war in the Pacific. In two big battles, in June  1944 in the battle of the Mariana Islands and in October 1944 in the battle of the Leyte Gulf, the Combined Fleet lost most of their aircraft carriers. The loss of the Philippines was subsequent proof demonstrating the superiority of the  United States in this conflict. The fleet of aircraft carriers without fuel and weapons has remained in their home bases. Eventually, the Japanese Empire without any real fighting force was on the verge of collapse. The final act of the  unconditional surrender was signed on September 2, 1945 on board of the American battleship „Missouri”.