Horace Vancil was Utapau Queen Sabé Arcadia's chief economic and political adviser, a member of the queen's Advisory Council, and a founding member of the Veermok Resistance during the Invasion of Utapau of 22 BBY. During the invasion, Vancil joined Ogana Governor Sio Bibble, Chief Architect Hugo Eckener, and Lieutenant Chamberlyn in founding the Veermok Resistance, a rebel movement that would launch insurgent strikes against the Trade Federation occupation forces. The Resistance was officially founded on the first night of the Rebellion in Ogana.
Vancil's reason for co-founding the Veermok Resistance was his regret over not being able to foresee the political consequences of supporting the anti-slavery measures, mainly the Federation's resulting invasion. He had suspected that the Federation leadership would be angered, considering the Federation used slave workers outside of Republic territory, but he was unable to foresee a military retaliation. He felt that he should not have blamed himself, but as the queen's adviser he also believed it was his fault that the planet had become involved in the slavery deliberations and that the planet was under siege.
- Star Wars: Episode I - The Chosen One (First appearance)