John C.G. Röhl is a British historian and author whose works focus mainly on 19th and 20th century German history, more specifically about Kaiser Wilhelm II. Röhl's first years were spent in Germany against the backdrop of World War II, and his first languages were Hungarian and German. He completed his national service as an airframe mechanic, and went on to earn his Ph.D in history, with his dissertation focusing on the history of Imperial Germany. Among his work is a prize-winning three volume biography of Kaiser Wilhelm II, written in German and translated into English, which is hailed as the Kaiser's definitive biography.