12edo is the predominating tuning system in the world today, so some of the 12th octave temperaments have been known for a very long time.
By far the most notable 12th-octave temperament is compton or aristoxenean, associated with the Pythagorean comma, which sets 3/2 to 7\12. Given that the circle of 12 fifths closing was the basis of music in Europe and independently China, it can be argued that the 12th-octave temperaments are the oldest form of musical tradition in history.
For temperament data, see:
Comma list: [-157 -24 84⟩
Mapping: [⟨12 2 23], ⟨0 7 2]]