Complex sentence: The Shah family of Nepalese kings had a history of animosity towards the Rana family, which had served as hereditary prime ministers of Nepal until 1951, with the title Maharaja.
Split into simpler sentences: The Shah family of Nepalese kings had a history of animosity towards the Rana family. The Rana clan had served as hereditary prime ministers of Nepal until 1951, with the title Maharaja.