This name originally indicated not a �royal� Trumpet, but a �real� trumpet in the sense of having full-length resonators, as opposed to Regals or the half-length Trompeta Bastarda. According Grove, it was mounted vertically within the organ, as opposed to en chamade. By around 1750 the name had come to mean �royal�.
Osiris contains scores of examples, nearly all at 8' pitch, some at 16' or 4'pitch, many horizontal. The earliest ones are listed below.