For the 2nd century Tanna

Tannaim

The Tannaim were the Rabbinic sages whose views are recorded in the Mishnah, from approximately 70-200 CE. The period of the Tannaim, also referred to as the Mishnaic period, lasted about 130 years...

 sage, see Haninah.

Hanina [Hananyah] Segan ha-Kohanim [the] Segan (Deputy) Ha-Kohanim (High priest)") was of the first Generation of the Jewish Tanna

Tannaim

The Tannaim were the Rabbinic sages whose views are recorded in the Mishnah, from approximately 70-200 CE. The period of the Tannaim, also referred to as the Mishnaic period, lasted about 130 years...

 sages. He lived during the destruction of Second Temple of Jerusalem, and had testified, following that event, on what he had seen occur on the Holy Temple. He was the son Rabbi Simeon ben ha-Segan. the book "Yihusei Tanna'im ve-Amora'im" cites that he was killed along with Shimon ben Gamliel

Shimon ben Gamliel

Simeon ben Gamliel was a Tanna sage and leader of the Jewish people. He succeeded his father Gamliel I as the nasi of the Sanhedrin after his father's death in 50 CE and just before the destruction of the Second Temple...

 and Ishmael ben Elisha ha-Kohen

Ishmael ben Elisha ha-Kohen

Ishmael ben Elisha ha-Kohen Elisha [the] Kohen Gadol "; sometimes in short Ishmael ha-Kohen, lit. "Ishamel the Priest") was one of the prominent leaders of the first generetion of the Tannaim. His father served as Kohen Gadol in the Second Temple of Jerusalem as well...

. It is said that he was one of the Ten Martyrs

Ten Martyrs

The Ten Martyrs refers to a group of ten rabbis living during the era of the Mishnah who were martyred by the Romans in the period after the destruction of the second Temple...

, and was killed on 25th of Sivan

Sivan

Sivan is the ninth month of the civil year and the third month of the ecclesiastical year on the Hebrew calendar. It is a spring month of 30 days...

 month on the Hebrew calendar

Hebrew calendar

The Hebrew calendar , or Jewish calendar, is a lunisolar calendar used today predominantly for Jewish religious observances. It determines the dates for Jewish holidays and the appropriate public reading of Torah portions, yahrzeits , and daily Psalm reading, among many ceremonial uses...

 ' onMouseout='HidePop("64080")' href="/topics/Arba'ah_Turim">Arba'ah Turim

Arba'ah Turim

Arba'ah Turim , often called simply the Tur, is an important Halakhic code, composed by Yaakov ben Asher...

 and Shulchan Aruch

Shulchan Aruch

The Shulchan Aruch also known as the Code of Jewish Law, is the most authoritative legal code of Judaism. It was authored in Safed, Israel, by Yosef Karo in 1563 and published in Venice two years later...

, Orach Chayim

Orach Chayim

Orach Chayim "manner of life" is a section of Rabbi Jacob ben Asher's compilation of Halakha , Arba'ah Turim. This section treats all aspects of Jewish law primarily pertinent to the Hebrew calendar...

 580).

Hanina earned his title due to the role he fulfilled - as Deputy to the Kohen Gadol

Kohen Gadol

The High Priest was the chief religious official of Israelite religion and of classical Judaism from the rise of the Israelite nation until the destruction of the Second Temple of Jerusalem...

 (High priest) in the Holy Temple of Jerusalem. Ha-Segan was a position with the responsibility of overseeing the actions of the work of the Temple's priests (Kohen

Kohen

A Kohen is the Hebrew word for priest. Jewish Kohens are traditionally believed and halachically required to be of direct patrilineal descent from the Biblical Aaron....

s) staff, as well as a stand-in position, ready to take the role of High priest in case he will be found unfit to serve the holy work on the temple. In that conjunction, Hanina was considered a "Segan Ha-Kohanim", only second to the High priest, as R. Hanina himself indicates:
At his time, many High priests reshuffled, while he remained in his role, and for that reason, it is believed to be the possible reason he was named 'Segan ha-Kohanim' rather than the more common term used in the Gemara

Gemara

The Gemara is the component of the Talmud comprising rabbinical analysis of and commentary on the Mishnah. After the Mishnah was published by Rabbi Judah the Prince The Gemara (also transliterated Gemora or, less commonly, Gemorra; from Aramaic גמרא gamar; literally, "[to] study" or "learning by...

: 'Ha-Segan'.