Duke Dermail is the head of the corrupt, aristocratic Romefeller Foundation and the main antagonist of the first half of Mobile Suit Gundam Wing. He greatly believed that to keep the peace, armed force must ensure tranquility in life.
He is first presented as the string-puller behind Treize Khushrenada and OZ. However, once the foundation begins to prosper and expand, Dermail starts to loose control of Treize, mostly due to Treize's objection to the foundation's interest in Mobile Dolls.
Duke Dermail eventually demands Treize's resignation and forces him into exile. Dermail's attention is soon after drawn to dealing with the rebellious Treize faction and the peace-oriented Sanc Kingdom.
He orchestrates the destruction of both through Operation Nova, a battle plan to send newly manufactured mobile doll armies from the foundation's lunar base to Earth to crush these rebellious forces.
After conquering the Sanc Kingdom, Duke Dermail gave it's leader, Relena Peacecraft an ultimatum. He forced her to become the chief representative of the Romefeller Foundation, in an attempt to replace Treize Khushrenada and unify the disjointed world forces under the foundation's control, including OZ. Relena accepted and became the first Queen of the Earth Sphere Unified Nation. Dermail's plan eventually backfired though, as the induction and counsel of Relena caused the other executives of the foundation to begin questioning Dermail's leadership and intentions.
After ordering the construction of the Libra battle station and being somewhat manipulated by his granddaughter, Dermail left to space to personal oversee the foundation's operations and prove himself to his Earth colleagues. However, on his way to Barge, his shuttle was intercepted by mobile dolls belonging to the newly emerged White Fang and Dermail was killed. He died as a coward.