Cloaked in mystery for 700 years.
In western history, there is hardly any ONE single group of individuals who are shrouded in more mystery, dread and suspense. Every other "occult order" since then have claimed to be connected, or related, to the Knights Templar.
How many volumes of books have been written about the Templars? How much speculation has been done? How much fantasy and imagination has been "sacrificed", speaking in terms of "psychic energy", on this idea that is the Knights Templar?
I have no doubt that the Doktor himself would have had a thing or two to say about the relative strength of performing L'Air d'Epais in synchronicity with a date which is very significant in connection with what little REAL information we have about these mysterious battle-monks.