Complex sentence: Lakshman Sen succeeded Ballal Sena in 1179, ruled Bengal for approximately 20 years, and expanded the Sena Empire to Assam, Odisha, Bihar and probably to Varanasi.
Split into simpler sentences: Lakshman Sen succeeded Ballal Sena in 1179 and ruled Bengal for approximately 20 years. He expanded the Sena Empire to Assam, Odisha, Bihar and probably to Varanasi.