The Collaborative International Dictionary of English v.0.48:

Earl marshal \Earl" mar"shal\
   An officer of state in England who marshals and orders all
   great ceremonials, takes cognizance of matters relating to
   honor, arms, and pedigree, and directs the proclamation of
   peace and war. The court of chivalry was formerly under his
   jurisdiction, and he is still the head of the herald's office
   or college of arms.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Earl Marshal
    n 1: an officer of the English peerage who organizes royal
         processions and other ceremonies