The Geonosian Legion was a volunteer legion in the Separatist Droid Army, fighting during the Clone Wars for the Confederacy of Independent Systems. It had some 104,000 members, split into 34 battalions, which were divided into 3 divisions. The Legion fought on numerous fronts during the war, and was the second biggest volunteer unit, along side the Human Legion. It was led by Gizor Dellso, an engineer who was called up by Poggle the Lesser to lead the legion for the CIS. The Legion fought alongside droids only, as it had negative relations with other volunteer units. The Legion later would become the basis of Dellso's Separatist holdouts.