Unusual assemblage of ink signatures on adjoining off-white 4.5 x 7 album pages. Royal signatures of key figures in World War I include: Rupprecht, Crown Prince of Bavaria and commander of the Sixth Army in France during World War I; Ludwig Ferdinand, Prince of Bavaria and General of Cavalry; Leopold, Prince of Bavaria and General Field Marshal who replaced von Mackensen and captured Warsaw in World War I, earning the Pour le Merite; Gisela, Archduchess of Austria; and Elisabeth, Princess of Bavaria. Opera signers include: Delia Reinhard; Berta Morena; Gabriele Englerth; Paul Bender; Wilhelm Rode; Otto Wolf; and one other. The adjoining page bears an elaborate signed ink sketch of an officer on horseback dressed for combat by painter Ludwig Koch, "Maler [painter] Ludwig Koch, April 15, 1931." In fine condition.