Kirigakure Civil War
The Kirigakure Civil War, although not the first actual civil war in the village is the most recent. Any reference to this war is assuredly towards this specific war. The civil war was orchestrated by Sekiryuu Minasoko, general of Kirigakure's D.E.A.T.H. army and self proclaimed Mizukage. In order to successfully place himself on the throne, Minasoko needed to take the village by force. His objectives were to kill Umikoi Warrusu za Shichi and Hisame Haruyuki as well as steal Hisame Shougo's bloodlines along with releasing Sanbi, the three tailed bijuu back into the world. Minasoko had also kidnapped Alchem Lily, presumably to use her as a host jinchuuriki.
Far Off Distance
Manasoko orchestrated a blitzkrieg type of attack, much like how the NCIA took over the world. This time, however, all of D.E.A.T.H.'s operatives were overwhelming compared to the shamble'd Kirigakurean shinobi force. His intiial attacks were to wake any of the previous Seven Shinobi Swordsmen of the Mist from their sleep and he had, Umikoi Warrugo. Warrugo had been corrupted over the years, seeking to infuse himself with natural energy without means of training due to his lust for battle. The natural energy warped him and he rose to fight Minasoko, he instead fought Kirigakure.
Warrugo blasted a tsunami through the Mizukage's Pavillion, digging deep beneath its crust to reveal the Sanctum of the SSS. It was where Minasoko had released Sanbi, trying to seal it back into a boy that they could control. There, Warrugo had reasoned the Shodai's Pearl may be, an item created by Namikaze Bodaijou to seal or control the Sanbi. The pearl wasn't found there and the Umikoi would meet his death by the hands of Warrusu and Haruyuki.
The Island of the Ten
This hidden island was the final resting place of the Shodai Mizukage. Upon the island were statues made in commemoration of the past Mizukage, honoring so far, to the tenth one. Minasoko had already gained a head start to search for the Pearl, but the search was much more difficult than he would expect. There were three entrances and three teams were made to traverse them. Each team would meet puzzles as their first challenges and cleared them. They found long hallways filled with dead, ancient languages that alluded to their second challenge. They would face a Guardian of the Pearl, each with a shard.
Aelilea, Nerues, Sailhem--His lover, his best friend, hist student. They were all related to the Shodai Mizukage in some way and each were asked to guard the shard for all eternity. The battles tested everyone to their breaking point. Kirigakure won the shards of Courage and Power, whereas D.E.A.T.H. claimed the shard of Wisdom. After the trail of the Gaurdians, all paths lead to one room. The Chamber of Interwoven Existence.
The Final Confrontation
The shinobi of Kirigakure and D.E.A.T.H. met in the crypt of the Shodai. Upon the meeting of the forces, Minasoko offered a deal to work together since they were effectively at a stalemate. Suddenly, the Sanbi broke free of its prison and entered the Chamber, forcing a battle to ensue. Alchem Syaoran offered himself as a willing host to control the Sanbi while the shards were given to Minasoko to reassemble. In one fell swoop, Minasoko sealed the Sanbi within Syaoran and used the pearl to control him. Disliking those odds, Haruyuki successfully shattered the pearl again and Sanbi ran rampant. The Sanbi-Syaoran was fought by Syaoran's essence Clone, Chao while Haruyuki engaged Minasoko and eventually slew the usurper.
Using the seven bloods of Kirigakure's nobel families as a ritual, Haruyuki reassembled the pearl and struck Syaoran with his sword, yanking out and sealing most of the Sanbi within the pearl. Not all of Sanbi's chakra had been sealed though. Enough remained within Syaoran to take control and wreak havoc another day.