The Yan-Isleth, or Brotherhood of the Sword, was an elite Klingon division charged with protecting the Klingon chancellor. They guarded the chancellor at all times. (DS9: "Apocalypse Rising") According to the script of the episode, the Klingon who Sisko shoots to protect Worf was a member of the Yan-Isleth. Furthermore, in the script's pronunciation guide, Yan-Isleth's name was pronounced as "YAN-is-LETH". [1]