License to Crenellate

Do you have a "License to Crenellate"? My very educated Pop-in-Law explained this one to me last evening as we sat contemplating which castles we would like to visit in the coming weeks. To Crenellate means "to provide battlements", so the requirement of a "License to Crenellate" means that one could not build a castle without the King's permission. All that's changed now, with the gentrification of the English countryside, but this requirement remained in force until the 16th or 17th century.

My archaeologist Father-in-Law went on to explain that during the time of the war between Stephen (grandson of William the Conquerer) and Matilda (the Empress Maud) - 1097 - 1154 - many adultarine, (isn't adultarine another good word?), castles were going up, which could not be tolerated by the king or queen of the time, and it was at this time that the licensing requirement came into effect.