Complex sentence: Chandragupta I, a Magadha king, and was the third ruler of Gupta Dynasty married a Lichhavi princess, Kumardevi which enabled him to gain a hold over the Ganges river-basin, the main source of North Indian commerce.
Split into simpler sentences: Chandragupta I, a Magadha king, was the third ruler of the Gupta Dynasty and married a Lichhavi princess, Kumaradevi. This enabled him to gain a hold over the Ganges river-basin, the main source of North Indian commerce.