Tivoli

Tivoli was the most conquered planet in the galaxy. It was inhabited by a species of rodent-like humanoids. They were one of the oldest civilisations in the galaxy and simply let invaders do as they wished. Their anthem was "Glory To  " and their cities were designed to be comfortable for the invading armies. It was green in colour when seen from space. (TV: The God Complex) Its capital city had a sign saying "If you occupied us, you'd be home by now." (TV: Before the Flood)

By 1969, the Dominators had conquered the Tivolians, (PROSE: Mutually Assured Domination) but were later conqured by the Fisher King and his people for ten years, before being liberated by the benevolent Arcateenians. The Tivolians did not take kindly to have those oppressing them removed from power. The Arcateenians became so irritated by the Tivolians that they chose to enslave them as well. An undertaker, Albar Prentis, was sent by them to bury the Fisher King on a "barren, savage outpost" in accordance with Arcateenian custom. (TV: Before the Flood)

Gibbis was a native of Tivoli, whose job involved planting trees so that invading forces would be shaded during their marches. (TV: The God Complex)