This chapter traces how the ancient common-law doctrines of champerty and maintenance have evolved from rigid prohibitions into more flexible principles of public policy. It examines how courts in both common-law and civil-law systems have reinterpreted these doctrines in light of contemporary litigation practices, distinguishing exploitative interference from legitimate funding mechanisms. Through an analysis of key judicial developments and statutory reforms, this chapter demonstrates how modern legal thought reconciles third-party litigation funding with the enduring objective of preserving the integrity of justice.