Summary

Cecil Weatherly 1911 Encyclopædia Britannica, Volume 20… (1911)

The essence of the pageant is that all who take part are residents in the place and locality, that the costumes and accessories should be made locally, and that all classes and all ages should share in a common enthusiasm for the bringing back in the most vivid form the past history, often forgotten, in which all should feel they have an equal and common part.
Source: Wikisource

Cecil Weatherly 1911 Encyclopædia Britannica, Volume 20… (1911)

The development in meaning from " moving platform " to that of a " processional spectacle " or " show " is obvious.
The 20th century has seen in England what may in some respects be looked on as a revival but in general as a new departure in the shape of semi-dramatic spectacles illustrative of the history of a town or locality; to such spectacles the name of " Pageant " has been appropriately given.
Source: Wikisource

Cecil Weatherly 1911 Encyclopædia Britannica, Volume 20… (1911)

Others take pagina as a translation of Gr. πῆγμα, platform, stage, a word from the same root pag-. Du Cange (Glossarium) quotes a use in Med. Lat. of pegma in this sense, Machina lignea in qua statuae collocabantur, and Cotgrave gives “Pegmate, a stage or frame whereon pageants be set or carried.”
As has been said, “pageant” is first found in the sense of a scene, a division or part of a play or of the platform on which such scene was played in the medieval drama.
Source: Wikisource

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