Duke Vethran of Gonfallon was a nobleman on Mendeb Three.
Kedin Ashar and Tevana Roslod made advanced weapons for Vethran in exchange for his promise to fund their further research. He used them to expand his power over the planet and attack its neighbour, Mendeb Two.
When rebels tried to overthrow Vethran, Ace was able to put some of the mind control drug SS10 into one of his drinks. Rendered a virtual automaton, Vethran's reign over the Mendeb system was ended. (PROSE: Independence Day)