why has Charles Darnay given up his inheritance?

Darnay feels that his family, particularly the Marquis, have taken advantage of others and treated people cruely because of their position in society and immeasurable wealth. He is appalled at the actions of his uncle and determined to live a different kind of life. Charles does not want to become a part of an oppressive system and chooses to renounce his family and walk away from his inheritance. His intent was to relocate in England where he could live an honorable life free from the taint he believes accompanies his family name.