Hanina [Hananyah] Segan ha-Kohanim [1] (Hebrew: ר' חנינא (חנניה) סגן הכהנים, lit.
"R. Hanina (Hananiah) [the] Segan (Deputy) Ha-Kohanim (High priest)") was of the first Generation of the Jewish Tanna sages.
It is also said that he was one of the Ten Martyrs, and was killed on the 25th of Sivan (late spring).
[2] Hanina earned his title due to the role he fulfilled - as Deputy to the Kohen Gadol (High priest) in the Temple.
Ha-Segan was a position with the responsibility of overseeing the actions of the work of the Temple priest staff, as well as a stand-in position, ready to take the role of High priest in case the incumbent was found unfit to perform his functions on the temple.