YUDENICH, NIKOLAI (1862-), Russian general, was born in 1862 and entered the army in 1881. Passing out of the General Staff College in 1887, he spent the rest of his military service on the general staff and specially in Turkestan, till in 1902 he became a regimental commander. In the Russo-Japanese War of 1904-5, in which he was wounded, he had the reputation of a valiant and careful chief. He became a general and commander of a rifle brigade in 1905, assistant chief-of-staff of the Caucasian military district in 1907, and chief of the same staff in 1913. Having carefully studied the Caucasus and its army, he was quite prepared for the conduct of operations on this front, and at the beginning of the World War he rendered great services in the crisis and victory of Sarikamish as commander of the II. Turkestan Corps. Soon afterwards he was put in command of all the military forces of the Caucasus, which he held during the operations of 1915 until the arrival of the Grand Duke Nicolai. He continued to serve on this front under the new governor-general and played a leading part in the operations which led to the fall of Erzerum on Feb. 16 1916. In the summer campaign further progress was made, and Baiburt and Erzinjan were taken. Later, when the advance had outrun the organization of the rear, the situation was saved by his prompt manœuvres.
In March 1917, on the departure of the Grand Duke, Gen. Yudenich again undertook the command of the Caucasian armies, but here, as elsewhere, further advance was paralysed by the increasing disorganization of the Russian army. In the course of the civil wars Gen. Yudenich in 1920 carried out a campaign from the Baltic provinces against Petrograd, but unsuccessfully.