Complex sentence: A few days before the massacre, upon insistence of Bhimsen Thapa, Rana Bahadur Shah, then 30 years old, had married a 16 year old girl named Tripurasundari, who was the daughter of Bhimsen Thapa's brother Kaji Nayan Singh Thapa.
Split into simpler sentences: A few days before the massacre, upon insistence of Bhimsen Thapa, Rana Bahadur Shah, then 30 years old, had married a 16 year old girl named Tripurasundari. The junior queen was the daughter of Bhimsen Thapa's brother Kaji Nayan Singh Thapa.