Rasmus was a Time Lord who once helped the Seventh Doctor capture the Eleven, at which point he had the title "captain".
Rasmus, now an undercardinal, met the Eighth Doctor on the research station Deeptime Frontier. He had a TARDIS. (AUDIO: Deeptime Frontier)
By the beginning of the Time War, he was a General on the War Council. (AUDIO: Desperate Measures)
Later on, as a Cardinal, Rasmus recruited Susan Foreman to the War. (AUDIO: Prequel)