Complex sentence: On September 6,1831, his disapproval of the popular excesses at Warsaw caused him to quit the government after having sacrificed half his fortune to the national cause; but throughout the Uprising he did not act up to his great reputation.
Split into simpler sentences: On September 6,1831, his disapproval of the popular excesses at Warsaw caused him to quit the government after having sacrificed half his fortune to the national cause. Throughout the Uprising, he did not act up to his great reputation.