Dren served under Char during the Zeon attack on Side 7 and was initially part of the Zeon forces pursuing White Base. After Char was reassigned following the death of Garma Zabi, Dren went back into space where he was promoted to Lieutenant to lead the Camel Squadron.
When White Base headed into space to assist the Earth Federation Forces fighting there, Dren and his men launched another attack on the White Base. During the battle, the RX-78-2 Gundam landed a strike on Dren's Musai-class vessel with the beam saber, splitting a hole into it that sucked Dren and several others out into space.
Principality of Zeon