Complex sentence: With changed circumstances over the years, the same British attacked the Belgaum fort, which was under Peshwas control, and held it under siege from 21 March to 12 April 1818, and took control of the fort and deposed the Peshwas.
Split into simpler sentences: With changed circumstances over the years, the same British attacked the Belgaum fort, which was under Peshwas control. They held it under siege from 21 March to 12 April 1818 and took control of the fort and deposed the Peshwas.