Green’s Dictionary of Slang

a beating, often in the context of a punishment.

1570		Demosthenes [trans.] Three orations n.p.: [note] King Philip practised stafford law with the people of Athens. Olynthians.
1589		Hay any Work for Cooper (1845) Aiij: By the swoorde I threatned him with blowes, and to deale by stafford law .
1599		N. Breton ‘The Scholler and Souldier’ Wil of Wit in Grosart (1879) 29/1: Among souldiers, Stafford law, martiall law, killing or hanging, is soon learned.
1605		P. Woodward Downefall of poperie 37: I wil stand vpon my lawful defence, and be readie to entertaine him, with Stafford law.
1624		P. Barker The ten Commandements 183: In other places they haue had Stafford law, and at Bridewell in our land whipping cheere.
1647		M. Corbet A Learned and Eloquent Speech in Harleian Misc. I (1808) 273: We have unlawfully erected marshall law, club law, Stafford law, and such lawless laws as make most for treason.
1681		J. Taylor A most learned and eloquent speech 5: [W]e have unlawfully erected Marshal Law, Club Law, Stafford Law, and such lawless Laws as make most for Treason, Rebellion, Murder, Sacriledge, Ruine, and Plunder.