In existographies, Horapollo (c.410-480) (LH:1), aka “Horus Apollo”, "Harapollo Nilius" (Cory, 1840), or "Harapollon" (Assmann, 2004), a named themed on the joint god Horus-Apollo, or Apollo as the Greek Horus, refers was a Roman-Egyptian priest, working under the reign of Flavius Zeno (470-491), the Eastern Roman emperor, noted for his Hieroglyphica (c.480), which gives 189 explanations, in Greek, of Egyptian hieroglyphs.
In c.480, Horapollo, in his Hieroglyphica, did an Egyptian to Greek translation of an Egyptian book, wherein he explained 189 of Egyptian hieroglyphs.
The following are quotes:
- “The name of Horae, Hours, came from Horus Apollo, an Egyptian sage, who first divided the day into those portions we call ‘hours’, as Macrobius (Saturnalia I.1.21) informs us.”
- — Thomas Powell (1661), Human Industry: a History of the Manual Arts 
- “European Egyptophilia started in the 15th century with the discovery of Horapollon's books on hieroglyphs (composed in late antiquity) and Marsilio Ficino's translation of the Hermetica (dating mostly from the 3rd century AD but believed to be of much higher date) and lasted until the decipherment of the hieroglyphs by Francois Champollion in 1822 and the subsequent establishment of Egyptology as an academic discipline. This second phase engaged in several most intense discourses on, or even dialogues with Egypt based solely on Greek and Latin sources. The most important foci of interest were theology, grammatology and political theory. Egypt became to be regarded as the origin and homeland of an arcane monotheism, a mnemonic writing system codifying ideas independent of language, and monarchy enlightened by wisdom and perfect laws. The sources for theology were mostly Hermetic writings, whereas the source for grammatology was Horapollon.”
- — Jan Assmann (2004), “Forward” to: Maat, the Moral Ideal in Ancient Egypt (pgs. xvii-xviii)
- “The word ‘Horus" in Irenaeus's discourse on the Marcosians, in which he relates that they ‘say that this is an image of Horus, encircling their thirty-named mother’, is often translated as ‘limit’, after the Greek word Horos or Ορος. The term for the god Horus used by Plutarch (38, 366A) and other Greek writers was in fact Ωρος — Horos. While pronounced the same, the two words are spelled differently in Greek, the term for ‘limit’ or ‘boundary’ starting with the Greek letter omicron (‘Ο’), while the Egyptian god's name begins with an omega (‘Ω’). Nevertheless, the word for ‘hour’ or ‘limited time’ is ωρα — hora — beginning with an omega, which would indicate that all three terms are cognates, especially since Horus himself has been identified with time, having been said to be the originator of 12 hours or ωρες / hares in the Greek, a word claimed by Horapollo to come from Horus’ name. Plutarch (38, 366A) also noted the correspondence between Hora and Horus, remarking: ‘The all-conserving and fostering Hora, that is the seasonable tempering of the surrounding air, is Horus.’ Plutarch's word ‘Hora’ is the same as that above, referring to a time period as well as a season or climate. Furthermore, the past tense of the ancient Greek verb ‘to limit’ — οριζω — is ωρισα, with an omega, the same as in the name Horus.”
- Horapollo. (c.470). The Hieroglyphics of Horapollo Nilous (translator: Alexander Cory). Whittingham, 1840.
- Author. (1862). “Review of Powell’s Humane History” (pg. 112), The Philobiblion, 1:111-14.
- Karenga, Maulana. (2004). Maat, the Moral Ideal in Ancient Egypt: A Study in Classical African Ethics (§Forward: Jan Assmann) (pgs. xvii-xviii). Routledge.
- Murdock, Dorothy. (2008). Christ in Egypt: the Horus-Jesus Connection (pg. 224). Publisher.
- Horapollo – Wikipedia.