Who was head of the War?

The phrase "head of the War" can refer to different leaders depending on the specific conflict in question. For example, during World War II, the Allied powers' key leaders included Franklin D. Roosevelt, Winston Churchill, and Joseph Stalin. In the context of the American Civil War, President Abraham Lincoln was the primary leader for the Union, while Jefferson Davis served as the president of the Confederate States. If you have a specific war in mind, please clarify for a more targeted answer.