I have been told by a POI, that they only look at recommendations from Professors. I am in the same boat - it's been a few years out of my MA in history. But the POI told me to just ask the professors for a recommendation.
With that being said. I had another professor tell me that because he didn't know the professors who recommended me he could not tell how much weight to put into the recommendations.
So my understanding is two fold: First, recommendations must be from professors. Second, those professors better be active within the field you are applying to.
This has me worried about my recommendations.