A medieval charter in which Reginald, King of the Islands (Mann and the Isles), formally acknowledges himself as liegeman to King John of England. The document is presented in both English and Latin versions, with witnesses including the Bishop of Winchester and several English magnates. An editorial note explains Reginald's political motivations: securing his throne against his brother Olave and gaining papal protection. This document establishes the feudal relationship between Mann and the English Crown that underpins later constitutional developments.