Nikolay Tchaikovsky was a hereditary nobleman, born in Vyatka. He graduated from the Physics and Mathematics Faculty of St. Petersburg University (1872). He took part in the student movement and 1869, he joined the revolutionary populist circle, which went down in history as a circle of “Tchaikovtsy”. In 1874–1907, Tchaikovsky was in emigration. One of the founders of the Free Russian Press Foundation in London, which published and sent to Russia revolutionary and forbidden literature. Since 1904, he was a member of the Socialist Revolutionary Party (SRs). In 1907, he returned to Russia in order to organize a guerilla war against the government and was arrested. 1910 saw Tchaikovsky acquitted. He left the Socialist-Revolutionary Party, retired from political activity, and took part in the cooperative movement. In 1916–1917, he worked in the All-Russian Union for Helping Sick and Wounded Soldiers.

After the February Uprising of 1917, he became a member of the Executive Committee of the Petrograd Soviet of Workers’ and Soldiers’ Deputies. He was an organizer of the 1st All-Russian Congress of Soviets of Peasant Deputies (May 1917). Tchaikovsky was a founder and member of the Central Committee of the Labour Popular-Socialist Party (June). He was elected a Deputy of the City Duma. He took part in the State Conference in Moscow (August) and the All-Russian Democratic Conference in Petrograd (September).

His response to the seizure of power by the Bolsheviks in October 1917 was negative. November saw him elected a Deputy of the Constituent Assembly. Tchaikovsky was a member of the Committee for the Salvation of the Motherland and Freedom, later of the Union for the Defense of the Constituent Assembly. In the spring of 1918, Tchaikovsky was a founder and leader of the Russian Revival Union in Moscow.

In August 1918 – October 1919, he headed the Supreme Directorate (since October 1918, the Provisional Government) of the Northern Region in Arkhangelsk. In the fall of 1918, he was formally a member of the Provisional All-Russian Government (Ufa Directorate). In January 1919, he was sent to Paris to attend the peace conference. In February–March 1920, he was a member of the South Russian government under General Anton Denikin. He took an active part in the activities of anti-Communist émigré organizations. Tchaikovsky died in London in 1926.