In the Orthodox Church tradition, as I understand it, the Feast of the 14,000 Martyrs commemorates the deaths of the children massacred by Herod in what is otherwise known as the 'Massacre of the Innocents'. (Matt 2:16-18).
Scholars have argued that the number was likely to have been in the 10s or low 100s. Where did the figure of 14,000 first come from? Why that number in particular?
At Warren's request in the comment below, here are some sources:
The Catholic Encyclopedia cites 3 figures: 64k in the Syriac tradition, 144k in the medieval tradition, based on Apocalypse 14:3 and 14k in the Greek tradition.
It's not beyond the bounds of probability that somewhere along the way 144k was reduced to 14k due to either scribal error or conservative judgement. It would be nice to trace the sources involved to check this theory out.
As far as the lower numbers go, there are some secondary sources quoted here and in this paper by Mans. The latter mentions an early low count given by Basil of Seleucia, but neither provide an answer to my question.
Mans notes the mention of a mass grave, and it seems there was a skeleton of one of the holy innocents included in Frederick the Wise's collection of relics.
I'm afraid these sources do more to widen the scope of the question than to narrow it.