"<ref name="before the flood"></ref> In the very distant past, the Time Lords fought a genocidal war against the Great Vampires, which led to such a catastrophic loss of life that the Time Lords renounced violence.<ref></ref> In "The War Games", the Second Doctor mentions that the Time Lords' "great powers" are hardly ever used due to their policy of non-intervention into the affairs of other planets, and that they instead observe and gather knowledge.