The Confederacy of Independent Systems is one of six playable factions in Sins of a Galactic Empire.
Wookieepedia article: Confederacy of Independent Systems
"The Republic cannot be fixed, m'lady. It is time to start over." ―Count Dooku, to Padmé Amidala
The Confederacy of Independent Systems, also known as the Confederacy, the Separatist Confederacy, the New Order, the pro-secessionists, colloquially as Separatists, Seps, Sepies, and the Separatist Alliance, was the government and separatist movement publicly led by Count Dooku, a.k.a. Darth Tyranus, (and secretly led by Darth Sidious) formed by various planetary and sectorial governments, as well as some mega-corporations, that declared intentions to leave the Galactic Republic, refusing to comply with its excessive taxation and corruption in the Senate during the Separatist Crisis.
Eventually, tensions between it and the Republic developed into war after Anakin Skywalker, Obi-Wan Kenobi, and Padmé Amidala were sentenced to execution on Geonosis and a group of Jedi led by Mace Windu attempted to rescue them. After the Republic revealed its clone army on Geonosis, the Separatists were forced to retreat, beginning a great war that would last for three years and tear the galaxy apart.
The CIS put fear in the hearts of countless citizens of the Republic, largely due to General Grievous, Supreme Commander of the Droid Armies. The Confederacy won many battles in the ensuing war but was dissolved when the Separatist Council leaders were killed on Mustafar, allowing Palpatine to reform the Republic into the Galactic Empire.
The CIS benefits from early game advantages such as kamikaze codes and decreased supply upkeep costs. They are mainly reliant on great technology upgrades, numbers and fighters with buzz droids that turn their rather ordinary fleet into something to be feared. Economic upgrades, which give them cheaper trade ports, shipyards, and extractors, as well as other advantages.