Jergal was the seneschal of Kelemvor, Lord of the Dead, whom he served just as he did Cyric and Myrkul before him. Jergal was the Lord of the End of Everything, Faerûn's original god of death before he eventually ceded his position to The Dead Three
"The throne is yours. I have grown weary of this empty power. Take it if you wish—I promise to serve and guide you as your seneschal until you grow comfortable with the position. Who among you shall rule?"