Octobrist, member of a conservative-liberal Russian political party whose program of moderate constitutionalism called for the fulfillment of the emperor Nicholas II’s October Manifesto. Founded in November 1905, the party was led by the industrialist Aleksandr Ivanovich Guchkov and drew support from liberal gentry, businessmen, and some bureaucrats. As the majority party in the third and fourth Dumas (1907–17), the Octobrists favoured a legislature with real power but insisted that the executive be responsible to the emperor only. The Octobrists, increasingly alienated from the government, finally joined the Kadets (Constitutional Democrats) in the Progressive Bloc of 1915, which called for more representative leadership and new reforms.