A 1610 Act of Parliament under James I confirming William, Earl of Derby's hereditary possession of the Isle of Man, its castle, lordship, and all associated rights, franchises, and revenues. The act extinguishes competing claims from the heirs of Ferdinando, late Earl of Derby, and establishes strict entailment to the male line. This document is fundamental to understanding the constitutional and property basis of the Earls of Derby's sovereignty over Man before the 1765 Revestment.