List of Lönchen of the Tibetan Empire
Tibetan Empire had nine high ministers in court. The highest one was gung lön chen po (གུང་བློན་ཆེན་པོ, lön chen (བློན་ཆེན) for short), which could be translated into English as "Chief Minister" or "Prime minister".
Source: Wikipedia — List of Lönchen of the Tibetan Empire (CC BY-SA 4.0)