Erkenbrand was one of the Rohirrim. At the time of the War of the Ring, Erkenbrand had retired from service to Théoden, but returned after the death of Théoden's son Théodred to command the forces of Rohan in its western regions. He later played a critical role in the Battle of the Hornburg when he and Gandalf lead an army of a thousand riders to reinforce the besieged forces of Rohan.
Erkenbrand is a name that comes from two Old English words: Eorcan (meaning "precious") and Brand (meaning "sword").
Erkenbrand does not appear in Peter Jackson's The Two Towers film. Instead, it is Éomer whom Gandalf sets out to find and returns with in the dawn of the final battle at Helm's Deep. However he does make a brief appearence in The Return of the King