I'm a big fan of conspiracy theories. The psychological motivations behind why people feel compelled to believe them, the intricacy and scale of them, the ability of believers to contort logic and fact to back up whatever assertions they have, it all fascinates me. I read David Aaronovitch's Voodoo Histories, which was a really interesting dissection and refutation of some of the biggest modern conspiracies, but I'd like to seek out more antiquarian ideas of sinister worldwide organisations. I mean, reading about how the Black Eyed Peas are paving the way for the coming of the cyborg master race in a land of perpetual war on Vigilant Citizen is brilliant and all, but I'd quite like to read something that explores the roots of some of these organisations without either aggressively dismissing their existence or foaming at the mouth to tell you how their tendrils are lodged in every aspect of your daily life.

So I know that conspiracies are one of those things everyone's in to now, like astrophysics and burgers and jogging, but does anyone know any good other books on the subject? Or have any favourite conspiracies/read anything interesting about it? I'm currently reading this article which has some...interesting ideas about the many shadowy factions embroiled in the Irish conflict over the years, overlaying it with even more strata of (crazy) intrigue.
http://www.taroscopes.com/miscellanous-pages/briefhistoryireland.html