Hi all, I'm researching the topic mentioned in the header.
What evidence is there that the Romans were in control of the Jewish priesthood to this extent, up to and including the time when it was still acting under the old covenant?
Although I was not looking specifically at this topic, it seems that one of the first dealings of Rome with the Jewish temple was when Julian the Apostate decrees the Jewish temple be rebuilt. But that's all I know.
According to Josephus (Jewish Wars) the Romans had considerable influence over who became - or didn't become - High Priest, although this was wielded through the vassal rulers of Judaea (primarily those of the Herod dynasty) who held the actual power of appointing temple officials.
I should add that the Herods' actions in this area were certainly influenced by other forces as well (historical - still appointing Levites; religious/temple politics; public opinion, etc.) - all, of course, which transpired under the sovereign will and immutable plan of God.