Frovian

The Frovians were a humanoid species with time travel capabilities. They were native to the planet Okul and ruled by Prince Luj.

They had a history of betrayal, appearing as benevolent allies to weaker species before crushing and enslaving them to pillage their resources. They had, on occasions, in the past, attempted to conquer worlds within the Kollian Dimension. However, under the rule of Prince Luj, the Frovians came very close to signing a peaceful agreement syncing the Kollian Dimension's timelines with those of their universe, an agreement which Gallifrey approved.

However, one of the Kollian delegates, Ux, discovered that Luj was still a bloodthirsty dictator, and his benevolent façade was a decades-old long con with the goal of laying waste to the Kollian Dimension once it was easily accessible. He hired an assassin, Kasgi, who attempted to kill Luj before he finalised the treaty. However, in the end, it was the Seventh Doctor, who had previously believed Luj to be a personal friend, who managed to stop the scheme, formally declaring that Gallifrey was no longer backing the Frovians and thus causing the other delegates to lose whatever faith they had in Luj's goood intentions. (COMIC: Who's That Girl!)

Behind the scenes
Frovians being a time-travelling species whose activities are ratified by Gallifrey suggests they were one of the Temporal Powers, although the name postdates Who's That Girl!.