In Fire & Blood, Otto Hightower’s beheading is described as a formal execution, but the book does not clearly name a specific person who swung the sword. The text says he was “the first to be beheaded,” which points to an executioner or another official doing it rather than Otto being killed in the same personal way the show portrays.

What the book says

  • Otto is executed after Rhaenyra takes King’s Landing.
  • The narration does not identify a named killer.
  • The wording suggests a traditional block-and-axe style execution, not a private duel or spur-of-the-moment killing.

Why people get confused

The TV adaptation shows Rhaenyra herself beheading Otto, but that is a change from the book’s more formal and less specific account.

Bottom line

So the honest answer is: the book doesn’t say who actually executed Otto Hightower by name ; it only confirms that he was beheaded as part of an official execution.