Magdalene

Smudge, the whole story about Mgdalene heading for France carrying Jesus' child is the a different secret society mostly involving the Priory of Sion. A good book is Holy Blood, Holy Grail

Thanks. I haven't read it though I am well briefed on its contents.
As for different secret societies, I am looking at similarities, the threads that connect the older groups, to try to establish a common theme that can perhaps trace them back to a single alternative viewpoint and hence a moment in time.
The Mary thing is just one of these common threads that ties aspects of the older groups together. John the Baptist is another. Sacred Geometry and King Soloman also feature highly. I tend to linger on a sub topic like Mary M/Mary Mother until I am satisfied that I can make a good case for using it as evidence. Many so called links turn out to be no more than modern misinterpretations of events that either never happened or that have been seriously embellished.
The search goes on.

many a true fact is hidden in fiction.

Ah yes that is most certainly true, it is the consistencies that tell the story.

The one connection that seems to common through a lot of the secret societies is a wanting to break away from the belief or government system of the time. The Illuminati and others were humanists. As for some others it seems that they were looking for answers that no one at the time or now can offer.

it appears that way, until you realise how far back they go. Then you can deduce that they are not in fact breaking away but continuing a long forgotten way.
It is because new groups spring from the old that it looks like a new group with a new philosophy.
When really it is a member of an old group who has stumbled on some aspect of his groups teachings that he needs to go off and pursue so sparking a breakaway.