he was born in kukush (present-day greece) 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.