Complex sentence: In 1819, Nawab of Mankera interested in the civil war of Marwats on the invitation of one party and later occupied the area for themselves.The very weakened Marwats were unable to resist the occupation and thus Marwats lost the independence.
Split into simpler sentences: In 1819, Nawab of Mankera interested in the civil war of Marwats on the invitation of one party and later occupied the area for themselves. The weakened Marwats were unable to resist the occupation and thus Marwats lost the independence.