The De Ceremoniis (fully De cerimoniis aulae Byzantinae) is the conventional Latin name for a book of ceremonial protocol at the court of the Byzantine emperors in Constantinople. Its Greek title is often cited as "Εκθεσις της βασιλείου τάξεως ("Explanation of the Order of the Palace"), taken from the work's preface, or Περί τῆς Βασιλείου Τάξεως ("On the Order of the Palace"). In non-specialist English sources, it tends to be called the Book of Ceremonies of Constantine VII Porphyrogennetos (variably spelt), a formula used by writers including David Talbot Rice and the modern English translation.
It was written or at least commissioned by Emperor Constantine VII (reigned 913-959), probably around 956-959. The compilation of Rep. I 17 (Leipzig, Universitätsbibliothek) was partially revised later under Nikephoros II (963-969), perhaps under the supervision of Basil Lekapenos, the imperial parakoimomenos, and it also contains earlier descriptions of the 6th century.