The name first appeared in a document of 1422 and has provoked much debate as to its origin. Although much publicity has been made that the Keys are the oldest parliament in the British Isles, it is not at all clear that they existed as a permanent body during the first two centuries of the Stanley era. During that time they appeared to have only a judicial function, apparently selected by the Deemsters, with the approval of the council, from the 'worthiest Men' in the Island. The name possibly arises from an English approximation to Yn Kiare as feed - 'the four and twenty' - their origin is in the period of Norse rule, originally 8 were chosen from the outer isles and 16 from Mann (probably one from each of the original 16 parishes). When the outer Isles were lost to Scotland in 1266 the lost eight representives were filled by Manx thus allowing four to be chosen from each sheading. Professor Carl Marstrander in the 1930's proposed however that it derived from the Norse Kuið, which he said was a typically Icelandic institution, brought to Mann with the Norse in late 9th Century; the Kuið being a highly placed jury, admission to which was restricted to men of landed property. Earlier, and less well based suggestions, have included Bishop Wilson's "The twenty-four keys, so called (it is said) from unlocking, as it were, or solving the difficulties of the law, represent the commons of the land, and join with the council in making all new laws, and with the deemsters in settling and determining the meaning of the ancient laws and customs in all difficult cases" which does however show their pre-reform dual legislative and judicial. roles.
Until the reform of 1867 the Keys were effectively self-appointing, many appeared to hold office for life or until being appointed to higher office. Members appeared to be chosen as representatives of leading families irrespective of place of residence (it was not even necessary to be resident on the Island). Sometimes the Lord excercised his prerogative to remove members. Post 1867 the Keys were elected for a fixed term of 7 years though vacancies are filled by bye-elections. Until the significant changes of the last 30 years, the House of Keys was the elected counterweight to the appointed Legislative Council under an all-powerful Lieutenant-Governor, and there were continual fights over control of finances. Today's title is M.H.K (Member of House of Keys) though earlier H.K. was used - S.H.K or Speaker of House of Keys was the leading position.
Ramsey B. Moore produced a list of Keys in 1933.