While secret leagues/organisations and age-old conspiracies are a tired trope, I'm trying to create a more realistic portrayal in a story I'm writing. However, I've stumbled upon a problem - funding. Where does all that money come from? For instance, in a high fantasy story... Let's say there's a conspiracy or rebellion building to overthrow the Dark Lord, as there always seems to be. How could they afford any of the materials they need? If they want a reasonably sized rebellion, especially against the forces of evil which wield cryptic black magic, they'd need a lot of warriors, magicians, strategists, etc. For this, they'd need a barracks with plenty of space. Then, they'd need to feed everyone, and they'd also need weapons, horses, funding for any magical research, said magical researchers, etc. How would they pay for all this without the Dark Lord noticing? Assuming they aren't part of or allied to any existing nation. Another concern I have is more modern settings, which the secret organisation trope seems to thrive. In urban fantasy, questions of technology, privacy, advanced weaponry and machinery, facilities, training, and so forth, all become very prominent. If the organisation doesn't want any nations knowing about its existence (or at least its true purpose), what method would it be able to use? Would it masquerade as a business? If so, what good/service would be most efficient for gaining money while staying mostly unknown? For both settings, I've been trying to wrap my head around the problem, but all the resources they need seem like they'd need a ridiculous amount of money.