Blagoev was also an important figure in the early history of Russian Marxism, and later founded and led the Bulgarian Communist Party.

[4][5] Blagoev was born in the village of Zagorichani in the region of Macedonia (today Vasiliada in Agioi Anargyroi, Kastoria, Greece), at that time part of the Ottoman Empire.

But by the autumn of 1883, reading the first volume of Das Kapital, by Karl Marx, and works by the German socialist Lassalle, and pamphlet Socialism and the Political Struggle written by the exiled Russian Marxist Georgi Plekhanov had converted him to Marxism.

[10] In 1883, Blagoev met and married the teacher, writer, and women's activist Vela Blagoeva (née Victoria Atanasova Zhivkova) with whom he would have four children: Stela, Natalia, Vladimir and Dimitur.

In 1893 this group, led by Yanko Sakazov, founded a reformist organization, the Bulgarian Social Democratic Union.

In 1894, Blagoev’s supporters agreed to unite with the Unionists in the interests of working class unity and took the name Bulgarian Social Democratic Workers Party.

He was a founder and became the leader of its left wing, which split from the BSDWP in 1903 to found the Bulgarian Social Democratic Workers' Party (Narrow Socialists).

A deputy to the National Assembly of Bulgaria, Blagoev voted in October 1914, along with the rest of the faction of narrow socialists, against war credits.

Blagoev was also author of a number of research essays on questions of Marxist philosophy, political economy, history, esthetics, and Bulgarian literature.