Megrati

The Megrati were a race who attempted to invade the planet Lemaria twice, with both attempts being stopped by the Doctor. The first attempted invasion was thwarted by the First Doctor. The Twelfth Doctor later learnt that an invasion fleet of Megrati were planning to attack Lemaria again. The Doctor sent them an invitation to give them some time to talk. While waiting for them to arrive, the Doctor took part in a Freedom Day celebratory play about the original defeat of the Lemaria, playing himself. The Doctor realised his fifth incarnation, Adric, Nyssa and Tegan Jovanka were in the audience before the real Megrati arrived. As his past self and companions watched, the Doctor convinced the Megrati to leave the planet by threatening to destroy their ships. (PROSE: The Constant Doctor)