Complex sentence: It was King Shahu of the Maratha Kingdom which first appointed a Peshwa to the' Chattrapatis (King), who began commanding Maratha armies and later became the hereditary rulers of the Maratha Empire from 1749 to 1818.
Split into simpler sentences: It was King Shahu of the Maratha Kingdom which first appointed a Peshwa to the'Chattrapatis' (King). The Peshwas controled the Maratha army and they later became the hereditary rulers of the Maratha Empire from 1749 to 1818.