He was born in Kukush and attended the Bulgarian Men's High School of Thessaloniki. After that he emigrated to the Principality of Bulgaria and graduated from secondary school in Belogradtchik. Vlachov also studied chemistry in Germany and Switzerland, where he took part in socialist circles. However, he graduated in these subjects from Sofia University. Here he enrolled in the Bulgarian Social Democratic Workers' Party. In 1903, Vlahov entered a military service in an officer's school in Sofia. Then he worked as a teacher in the Bulgarian Men's High School of Thessaloniki where he was active in IMRO. During this period, he was arrested by the Ottoman authorities. In 1905, Vlahov was released and went back to Bulgaria where he worked as a teacher in Kazanlak. In 1908, after the Young Turks revolution he began working in the Bulgarian secondary school in Thessaloniki again. In the next few years, Vlahov was politically active as a member of the Ottoman Parliament as a representative from the People's Federative Party. After the dissolution of the PFP in 1911, he became a member the Ottoman Socialist Party and in 1912 was elected again as a deputy in the Ottoman Parliament. After the Balkan Wars, Vlachov was a representative of the Kingdom of Bulgaria in high diplomatic and administrative positions in Odessa, Kiev, Pristina and Vienna. After World War I and the reestablishment of IMRO in 1920, Vlahov was elected as alternate member of its Central Committee, representing the left wing. At that time he was a Secretary of the Chamber of Commerce in Varna. Todor Alexandrov urged him to establish a contact between IMRO and Soviet Russia. As a messenger served Krastyo Rakovski, his best man and prominent figure of the Comintern. On behalf of IMRO, Vlahov departed in July 1923 to Moscow. So in 1924, IMRO entered negotiations in Vienna with the Comintern about collaboration between the communists and the Macedonian movement and the creation of a united Macedonian movement. Vlahov helped the subscription of the so-called May Manifesto about forming a Balkan Communist Federation and cooperation with the Soviet Union. After the subsequent rift between the organization and the Communists, the new leadership headed by Ivan Mihailov excluded him from the organization and he was sentenced to death. In 1925, he was one of the founders of the IMRO in Vienna. He also became a member of Bulgarian Communist Party. During the late 1920s, he worked in France, Germany and Austria as a Comintern publicist. During this period he was chased by IMRO and against him were organized several failed assassination attempts. In 1932 members of IMRO, put for the first time the issue of the recognition of a separate Macedonian nation in a lecture in Moscow. The question was also studied in the highest institutions of the Comintern and in the autumn of 1933, Dimitar Vlahov arrived in Moscow and took part in a number of meetings. So on January 11, 1934, the Political Secretariat of the Comintern adopted a special Resolution on the Macedonian Question. From 1936 to 1944, Vlahov lived in the Soviet Union and in 1944 he went to the new Yugoslavia with Socialist Republic of Macedonia, where he worked in high state and political positions. In 1948 on a meeting of the Central committee of the Macedonian Communist Party he claimed that the decision by the IMRO from 1932 on the formation of a separate Macedonian ethnicity was a political mistake. Later, he was gradually pushed out of his power positions from the pro-Yugoslav circle around Lazar Kolishevski. Vlahov died in Belgrade in 1953.
