Rudolf Gajda was a descendant of nobility, born in Kotor, Austria-Hungary (currently Montenegro). His father was a Moravian German, and his mother was a Montenegrin noblewoman. He studied at the gymnasium. Upon the outbreak of World War I, he was drafted into the Austro-Hungarian army. In 1915 Geidl was captured and defected to the Montenegrin army. In 1916, he fled to Russia with forged documents. He joined the Serbian Volunteer Corps, formed in 1916 from former servicemen of the Austro-Hungarian army, to fight on the side of the Entente. In December 1916, he joined the Czechoslovak Rifle Brigade with the rank of staff captain. He took a new name, Radola Gajda. He participated in the June offensive of 1917. He was awarded the Order of St. George, 4th degree for his actions in the Battle of Zborov.

In the spring and summer of 1918, he was an active participant in the Czechoslovak Legion’s armed uprising in the east of Russia. In July 1918, in the area to the east of Omsk, colonel Radola Gajda took command of the troops, which included both Czechoslovak legionaries and Siberian opponents of the Bolsheviks, who had joined them. At the end of August 1918, Gajda’s units joined the Czechs, who were advancing from the east, as well as the troops of General Mikhail Diterikhs. Gajda was promoted to Major General in 1918.

In 1918, the forces under the command of Gajda took part in the battles for Irkutsk, Yekaterinburg, and Perm. He was awarded the Order of St. George, 3rd degree. Since October 1918, Gajda commanded the Yekaterinburg group of forces of the Siberian Army of the Provisional Siberian Government, and later the army of the Provisional All-Russian Government (Ufa Directorate). Lieutenant General (1919).

Since January 1919, Gajda served in the Russian Army of Aleksander Kolchak. As the Commander of the Siberian Army, he led the offensive on Vyatka and Kazan (the spring of 1919). He would not fulfill Kolchak’s order to suspend the offensive and provide support to the Western Army, which was one of the reasons for the defeat of the troops of the Russian Army’s Eastern Front. In July 1919, he was removed from the command of the Siberian Army and briefly arrested. Soon he was released, dismissed from the Russian Army, stripped of all awards and General’s rank.

In November 1919, in Vladivostok, he tried to revolt against Kolchak with the Socialist-Revolutionaries (SRs). He was arrested, released under pressure from the allies, and left Russia.

In 1920–1926, he served in the army of Czechoslovakia. He acted as Chief of the General Staff (1926). Gajda took part in the fascist movement. Due to a conflict with President Tomáš Garrigue Masaryk, he left office and was in opposition to the government of Czechoslovakia. In 1945, he was accused of aiding the German invaders. He died in Prague after the release.