Here’s a piece of the text from the grimoire card Ghost fragment: Cabal. I’m quite sure that this card is from vanilla destiny 1. There is a vast Empire behind these creatures, many star systems away. Some pledge allegiance to that far Empire, obeying their ancient marching orders. Some do not. They disagree among themselves about the answers. I wish arguing Cabal on no one. They slam their plated bodies into each other with horrendous roars. Intelligence gathering has never been so painful. This could mean that the midnight coup, where ghaul dethroned Calus and took over Cabal empire happened while the cabal were fighting on Mars and that somehow they had found about it. But it could also mean that the Coup happened before any of the legions were send on Mars. And that almost immediately after it Ghaul send the legions to Mars. This would explain why the cabal had disagreement like it says on the grimoire card. This is a piece of the grimoire card Ghost fragment: Cabal 3 that came with the Taken king “I have my orders. Our report went all the way up, and the decision came all the way back.” Valus Tlu’urn’s blank helmet swivels to stare. “You mean — ?” “It came from the Emperor Himself.” Ta’aun can feel the pressure gel pumping against his skin, keeping him insulated from this deadly world, keeping him alive. “I’m ordered to board and capture the Hive flagship. At any cost.” In this card we see the primus of the skyburners Ta’aun telling that the emperor himself responded to their report and ordered them to board the dreadnought. This would hint that Calus was still in power when this happened because Ghaul didn’t want to be called emperor when he took over. He named himself Dominus. Now if we assume that Calus was still in power when the taken king happened, it would mean that Ghaul took over the cabal empire at sometime between the taken king and destiny 2. But this just doesn’t feel right to me. Wasn’t the cabal empire more peaceful during Caluses reign? Why would he sent his legions to fight so far away from their homeland if he wasn’t even fighting that much closer to his home planet. Could it just be that the cabal still referred to Ghaul as the emperor even if he didn’t want that title for himself?

This is one thing that for now is up to personal interpretation I believe that the midnight coup happened before the events of destiny so ghaul sent the Cabal to the system and when the message is sent to the emperor it is sent to ghaul even though he has the title of dominus

That's actually a really good question. In Destiny 1 there's a mission on the Dreadnought where the Cabal are sending an emergency message to the emperor, but Ghual is a Dominus which is essentially the same thing but not in the eye's of Cabal society Calus seems like a anti-war type of guy but he's the only one who fits the title of emperor Maybe it was Consol and the council that lead the Cabal before Calus? But then why wouldn't Calus tell the Cabal to leave Sol after he took over?! I have absolutely no idea

I would assume ghaul. He had control over the cabal empire at the time and it would make sense for him to send them to sol. Could be a case that he located the traveler and decided to send the 6 legions (dust giants, sand eaters, skyburners, ice reapers, blind legion and the siege dancers) to sol as a means to obtain it. Obviously we intervened and when Oryx came they realised that the Hive And guardians are both too strong a force. So they called for reinforcements and Ghaul pulls a thanos and does it himself.