Is eta in Ancient Greek transliterated as long e or h?

Question

Is eta in Ancient Greek transliterated as long e (e.g. https://pressbooks.bccampus.ca/greeklatinroots2/chapter/%c2%a798-the-greek-alphabet/), or h (e.g. https://www.dictionary.com/e/greek-alphabet-letters/)?

Answer 1

In the Phoenician script, the letter heth represented a consonant sound, /ħ/.

When the Phoenician script was adapted to write Greek, this letter was generally also used for a consonant sound, something like /h/. This is where the Latin letter H comes from (the Latin alphabet was adapted from the Etruscan alphabet which was adapted from the Greek alphabet).

However, this adaptation process also involved repurposing various consonant letters to indicate vowels (which the Phoenician script didn't do). The Ionian dialect had lost the consonant /h/, and thus repurposed heth alongside the others, creating eta.

Later, around 400 BCE, the Ionian alphabet began to displace other local alphabets, and eventually became a de facto standard—even in the dialects that still had a /h/ sound.

As a result, Greek eta is related to Latin H, but is a vowel, not a consonant. The best transcription depends on the context (H is easier to type than Ē) but for non-specialists it's generally better to make it clear that it's a vowel.

Answer 2

Ancient Greek η is standardly transliterated as e, or as ē in case diacritics are allowed in transliteration. For example ἐπᾰγωγή could be epagoge or epagōgē, but the latter is rather atypical / non-standard (though academically not totally rare).