"Grant, of special grace, to William de Excestre, king's clerk, prebendary of Rikhall in the church of St. Peter, York, and to his successors of a weekly market on Wednesday at their manor of Rikhall, co. York, and of a yearly fair there on the vigil, the day and the morrow of Saint Margaret the Virgin: licence also to the said William to fortify his house (mansum) of Rikhall with a wall of stone and mortar and to crenellate it, and in that state to hold it to him and his heirs without let or hindrance of the king and his heirs or any their ministers."
Granted at Westminster, by King.
Original source is
(In fact, the original source given is usually a transcription/translation of what are precious medieval documents not readily availably. It should be noted that these transcription/translations often date to the nineteenth or early twentieth centuries and that unwitting bias of transcribers may affect the translation. Care should also be taken to avoid giving modern meaning to the medieval use of certain stock words and terms.)
Significant later source are;
More details about licences to crenellate can be found here.
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