Arbiter of Succession

From Memory Alpha, the free Star Trek reference

The Arbiter of Succession is an individual selected by the leader of the Klingon Empire to oversee the Rite of Succession after his/her death. The Arbiter also officially confirms the next leader, who is selected by the Klingon High Council.

In 2367, Captain Jean-Luc Picard oversaw the Rite of Succession and subsequent installation of Gowron. (TNG: "Reunion", "Redemption")