The qui tam mechanism traces to a 695 AD Anglo-Saxon decree of King Wihtred of Kent that paid an informer half a Sabbath-breaker's fine

Qui tam — the device, still live in the US False Claims Act, that lets a private citizen sue on the government's behalf and keep part of the penalty recovered — is far older than the "private attorney general" vocabulary now attached to it. The Congressional Research Service dates its earliest cited instance to Anglo-Saxon England: "The earliest cited example of a qui tam provision is the 695 declaration of King Wihtred of Kent, which stated that 'If a freeman works during the forbidden time [i.e., the Sabbath], he shall forfeit his healsfang, and the man who informs against him shall have half the fine.'" The informer's cut — half the forfeited healsfang — is the load-bearing feature: enforcement is privatized by making it profitable to report a violation.

The same bounty logic runs forward through medieval English informer statutes to Abraham Lincoln's 1863 False Claims Act, whose qui tam clause a sponsor justified (per the same CRS report) as the "old-fashion idea" of "setting a rogue to catch a rogue." The through-line across 1,275 years is a single design: the state deputizes self-interested private parties as enforcers by giving them a share of the recovery.

This bounty-driven ancestry is what makes the 1970 Clean Air Act's no-bounty citizen suit a structural sibling reached by an unrelated route — see claim-1970-clean-air-act-citizen-suit-invented-against-regulatory-capture and the convergence itself in observation-privatized-law-enforcement-reinvented-without-shared-lineage. That pairing is a live test case for the vault's multiple-discovery cluster and its rival, Chandler's transmissionist thesis.