In last night's chat, we discussed proskynesis under Roman emperors and wondered where Diocletian and the other tetrarchs got the idea.
It originated with the Persians, as Jona Lendering points out in Proskynesis: Greek name of the ritual greeting at the eastern courts.
The tetrarchs, in the course of their extensive reforms, became living gods (dii geneti et deorum creatores) and thus began practicing an elaborate court ritual to to emphasize their distance from the ordinary mortals.
Further search brought to this BMCR review:
Frank Kolb, Herrscherideologie in der Spätantike. (the ideology of rulers in the late antiquity) Berlin, Akademie Verlag, 2001. Pp. 274. ISBN 3050034327, and I quote this:
Even proskynesis in the presence of the emperor, said by a number of sources to be an innovation of Diocletian, appears to have been practiced informally as early as the reign of Septimius Severus (pp. 39-40). This is not to say that Diocletian and the tetrarchy produced nothing new; among the innovations of the period were the wearing of purple as an imperial attribute, and the stress on the similitudo and concordia of the emperors in contemporary literary and artistic propaganda (pp. 32-33; 49). In general, however, Diocletian and his colleagues took various preexisting trends and molded them into a new and formal court ceremonial emphasizing the exalted status of the ruler in tetrarchic ideology.
Pat Southern, in The Roman Empire from Severus to Constantine, discusses the ‘evolutionary path towards autocracy’ in the chapter The Empire Transformed.
The image on top represents “Proskynesis: King Jehu of Israel doing homage to Shalmaneser” (British Museum)
[Googling for proskynesis also led me to the rather strange piece Monarchy and War, Erik von Kuehnelt-Leddihn, Journal of Libertarian Studies Volume 15, no. 1 Fall 2000]