Complex sentence: Sanjo died while still in confinement at the temple; and after learning of his death, Komei sent Imperial envoys to Nisonin to elevate the late-courtier to the posthumous rank of Udaijin.
Split into simpler sentences: Sanjo died while still in confinement at the temple. After learning of his death, Komei sent Imperial envoys to Nisonin to elevate the late-courtier to the posthumous rank of Udaijin.