Yuri Danilov was born in 1866. Danilov joined the Russian Army and in 1910 was the principal author of what became known as Plan 19. Danilov argued that on the outbreak of war in Europe the German Army would concentrate its forces against France. Danilov therefore suggested that four of its armies (19 corps) should immediately invade East Prussia.

Some leading members of the Russian Army disagreed with the tactics of Plan 19. They argued that Austria-Hungary represented a greater threat to Russia than Germany. In 1912 it was decided to substantially alter Plan 19. Only two armies were now to attack East Prussia with the rest concentrating on defending Russia from the Austro-Hungarian Army.

On the outbreak of the First World War Danilov was appointed deputy chief of staff under Grand Duke Nikolai. Danilov was given responsibility of co-ordinating offensive operations on the Eastern Front. Danilov, who achieved little success, was removed from office when Tsar Nicholas II took control of the Russian Army in September 1915.

In 1915 Danilov was sent to the northern section of the Eastern Front and eventually commander of the Fifth Army. Danilov retired from the Russian Army in the autumn of 1917. In 1918 Yuri Danilov emigrated to France where he lived until his death in 1937.