In 1912, Mgeladze, together with Grigol Uratadze, was part of the Georgian delegation to Vienna, where Leon Trotsky organized his short-lived union of social democratic factions as an alternative to Lenin's narrow notion of party unity. After the 1917 October Revolution which swept the Bolsheviks to power, Mgeladze withdrew into energetic opposition to Lenin and returned to his native Georgia, where he became involved in the politics of the independent Democratic Republic of Georgia whose government made him a commissar for the People's Guard of Georgia. The 1921 invasion by the Soviet Russian army forced Mgeladze into exile to France, where he died in 1943.