This text comes from The Poetical Works of John Keats, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Otho the Great, Emperor of Germany
An Hungarian Captain.
Ludolph, his Son.
Physician.
Conrad, Duke of Franconia.
Page.
Albert, a Knight favored by Otho.
Nobles, Knights, Attendants, & Soldiers.
Sigifred, an Officer, friend of Ludolph.
Theodore and Gonfred, Officers.
Erminia, Niece of Otho.
Ethelbert, an Abot.
Auranthe, Conrad's Sister.
Gersa, Prince of Hungary.
Ladies and Attendants.
Scene.—The Castle of Friedburg, its vicinity, and the Hungarian Camp.
Time.—One day.