At the beginning of the last century, the French president and the German emperor never used to meet. Paris had not digested the kidnapping of Alsace-Lorraine. This distance favored misunderstandings and the smallest dispute could take on an inordinate magnitude. Between 1899 and 1914, Prince Albert I of Monaco and the pacifist Bertha Von Suttner, the first woman to win the Nobel Peace Prize, worked behind the scenes to bring France and Germany closer together. They would try everything with Kaiser Wilhelm II and the Elysée Palace to avoid a war with devastating consequences... The diary of Albert I was kept hidden from sight in the archives of the palace of Monaco until now and offers an unprecedented testimony to this fascinating "fight for peace".