See before I'd have recommended you watch a certain someone's videos on L'manberg (because that's when it starts to pick up) but now you can't really do that so it's tommyvods and tommyinnit.
So Wilbur Soot creates a breaking-bad style drug caravan called the 'camarvan' (later called the 'hto dog van') which he and TommyInnit use as a 'disposal unit' for potion stands/ingredients which they claim lead to really bad diarrhoea but really they're attempting to hold all the potion paraphernalia on the server so they hold the monopoly.
They successfully scare Tubbo into giving over his potion stuff but Sapnap is with him and grabs the blaze rods Tubbo gives over next. Tommy and Wilbur call him Cracknap and claim he's an addict.
Sapnap becomes a self-proclaimed cop and investigates the van, proving to Tubbo and Fundy (who was also watching suspiciously) that it's a drug van, not a disposal unit. Sapnap tries to hunt them down and kill them but they hide underwater.
They invite other people to the van (Tubbo, Fundy, Eret and later Niki) and aim to get independence against the Dream SMP after building walls around the van. They do this as they're stopping them from doing what they want to do (which was originally to sell drugs but now Wilbur's making it all about freedom and liberty because that sounds better). This kicks off the revolutionary war.
Before all this happened, Dream and Tommy were involved with the disc wars, hence why their duo name is discduo. More or less, they were fighting for ownership of the discs cat and mellohi. Others were involved but it was mostly just them two who actually cared.
By the time of L'manberg, Tommy had cat and mellohi and Dream engages heavily with the war in L'manberg because Tommy's involved and he wants the discs/control of Tommy. For Tommy to be legally free from him is not obviously what Dream wants. So when Dream leaves a recording (that states that he wants to see 'white flags...by dawn or you're dead') he first greets Tommy, then the rest of L'manberg, making it abundantly clear it's about Tommy.
Tommy leads the fight but it doesn't go well because they can't get the high ground, they're poorly-equipped by comparison and Dream and other people on the Dream SMP are quite good at fighting.
So the war is already going badly for L'manberg. They've been killed so they've lost all their stuff; L'manberg's been partially blown up (after Dream lit 'one little TNT' which turned out to have been rigged to a ton of TNT planted underground) and so Eret takes them to the place that will be their saving grace. The Final Control Room.
He has put chests there for everyone, named so they know which belongs to each of them. Then Tommy spots a strange button and presses it. Dream, Punz, Sapnap and George come out of the walls and start killing them, even thought they're basically unarmed. Eret says 'down with the revolution, boys. It was never meant to be', betraying them and joining in with the attack.
Dream is the one to kill Tommy.
Everyone else believes there's no hope and the war is over but Tommy angrily negotiates with Dream, challenging him to a duel. If he wins, L'manberg gets their independance (as they spell it) and if Dream wins, he gets one of Tommy's discs. They duel; Tommy loses.
Suddenly, it's feeling even more hopeless.
But Tommy negotiates with Dream again, only telling Wilbur when he has secured their independence for his other disc (a very selfless act as everyone admits).
So now they have independence, but people don't respect Wilbur as a leader. So to consolidate power, Wilbur plans elections. Wilbur will run for president; Tommy will be his runningmate.
So that's the gist of the revolutionary stuff.