Gandorans were an ancient reptilian species native of Mars that inhabited the city of Gandor. They were the creators of the Ice Warriors, who were originally their slave race. Gandorans needed to consume a substance known as life drink to survive.
By the time the Second Doctor, Jamie and Zoe visited Gandor, it was the last city on Mars, previously home to many other civilisations. Zaadur, a daughter of Gandoran scientist Quendril, became a dictator by taking control of life drink supply and rationing it. Later, she decided to conquer Earth with her army of Ice Warriors and kill all other Gandorans, whom she considered imperfect, as they were not genetically engineered as she was. (AUDIO: Lords of the Red Planet)