Complex sentence: Particularly notable was his involvement with the 1907 Tiflis bank robbery, which resulted in 40 deaths and the theft of 341,000 rubles (roughly US $3.4 million when adjusted for inflation); the incident would have long-lasting ramifications for his political career.
Split into simpler sentences: Particularly notable was his participation in the 1907 Tiflis bank robbery, which resulted in 40 deaths and the theft of 341,000 rubles (roughly US $3.4 million when adjusted for inflation). The incident would have long-lasting ramifications for his political career.