After the
October Revolution of 1917, Yudenich went into hiding from the
Bolsheviks and was sheltered by a former sergeant of the Life Guards of Lithuania, who had served with Yudenich from his time in the
Pamirs. He managed to escape to exile in
Finland in January 1919. In
Helsinki, Yudenich joined the "Russian Committee," which had formed in November 1918 to oppose the Bolsheviks, and he was proclaimed as leader of the
White movement in
northwestern Russia with absolute powers. In the spring of 1919, Yudenich visited
Stockholm, where he met with diplomatic representatives of Britain, France, and the United States and tried with limited success to obtain assistance in developing a Russian volunteer corps to fight the Bolsheviks. In June 1919, Yudenich made contact with Admiral
Aleksandr Kolchak's All-Russian Government based in
Omsk, which subsequently acknowledged him as commander-in-chief of all Russian armed forces operating against the Bolsheviks in the
Baltic Sea and in northwestern Russia. Kolchak also provided much-needed funds to pay and equip his forces. In June 1919, Yudenich went to
Tallinn to meet with General
Aleksandr Rodzyanko, the commander of the White Russian Northern Army,
attacking Petrograd formally under the
Estonian High Command. Yudenich appointed Rodzyanko as his aide. In August 1919, under pressure from the British government,
ad hoc to issue a legally-binding guarantee of the independence of his key ally
Estonia, Yudenich was forced to create the
counterrevolutionary "
Regional Government of Northwest Russia," which included monarchists, Socialist-Revolutionaries, and
Mensheviks. Yudenich served as Minister of War and spent the next two months organizing and training his army. By September 1919, he had a fairly well-organized army of approximately 17,000 troops, with 53 guns and six tanks. The six
tanks were supplied by Britain, together with their volunteer crews, who were the only British ground troops to fight alongside the Northwestern Army. In early October 1919, Yudenich
launched his army against Petrograd, which was only lightly defended, as the
Red Army was actively engaged on several other fronts in fighting Kolchak's forces in
Siberia and several
Cossack armies in
Ukraine. Yudenich's friend from the Imperial Russian Army, General
Carl Gustav Emil Mannerheim, asked Finnish President
Kaarlo Juho Ståhlberg to join Yudenich's force and to attack
Petrograd with help from the
Finnish White Guards. Yudenich would have recognized Finland's independence, and the country's pro-
Triple Entente relationships would be recognized. As Kolchak, nominally the leader of the White Armies, would not recognize Finland's independence, Stålhberg denied Mannerheim's request. Overall, the Northwestern Army was nationalistic and patriotic and thus rejected ethnic particularism and separatism. The Northwestern Army generally believed in a united multinational Russia and opposed separatists wanting to create
nation-states. On 12 October 1919, the Whites retook
Yamburg (now Kingisepp). Two days later, Yudenich was approaching
Gatchina. On 19 October 1919 his troops reached the outskirts of Petrograd, but his forces failed to secure the vital
Moscow – Saint Petersburg Railway, which allowed the
Revolutionary Military Council to send in massive reinforcements to prevent the fall of the city. Yudenich's stalled offensive collapsed in late October, and the 7th and the 15th Red Armies repulsed the White Russian troops back into Estonia in November. Distrustful of the White Russians, the Estonian High Command disarmed and interned the remains of Northwestern Army, which retreated behind Estonian lines. Politically, the Bolsheviks secured a separate armistice with
Estonia on 3 January by promising to recognize Estonian independence, an offer contrary to the White Army's and the Kolchak government's position. During the civil war, like many other generals, Yudenich issued currency to pay his troops. They were reported to be so worthless that a
Tallinn chocolate company requested permission to use the banknotes as wrappers for its products. On 28 January 1920, General
Stanisław Bułak-Bałachowicz, together with several Russian officers and the
Estonian Police, arrested Yudenich as he tried to escape to
Western Europe. Yudenich was later released from prison. ==Later life==