Mishneh Torah — Transmission of the Oral Law מסירת תורה שבעל פה, Chapter 7

בֵּית דִּינוֹ שֶׁלְּעֶזְרָא, הֶם הַנִּקְרָאִין אַנְשֵׁי כְּנֶסֶת הַגְּדוֹלָה. וְהֶם חַגַּי זְכַרְיָה וּמַלְאָכִי, וְדָנִיֵּאל חֲנַנְיָה מִישָׁאֵל וַעֲזַרְיָה, וּנְחֶמְיָה בֶּן חֲכַלְיָה, וּמָרְדֳּכַי, וּזְרֻבָּבֶל; וְהַרְבֵּה חֲכָמִים עִמָּהֶם, תַּשְׁלוּם מֵאָה וְעֶשְׂרִים זְקֵנִים. הָאַחֲרוֹן מֵהֶם הוּא שִׁמְעוֹן הַצַּדִּיק, וְהוּא הָיָה מִכְּלַל הַמֵּאָה וְעֶשְׂרִים, וְקִבַּל תּוֹרָה שֶׁבְּעַל פֶּה מִכֻּלָּן; וְהוּא הָיָה כּוֹהֵן גָּדוֹל, אַחַר עֶזְרָא.

[The members of] Ezra's court are referred to as Anshei K'nesset Hagedolah (the men of the great assembly). They included Chaggai, Zechariah, Malachi, Daniel, Chananiah, Mishael, Azariah, Nechemiah ben Chakaliah, Mordechai the linguist, Zerubavel and many other sages - 120 elders in all. presided over the return to Zion at the beginning of the Second Temple period and set the foundations for the reconstruction of the nation.The last [surviving] member of this group was Shimon the Just. He was included among the 120 elders and received the Oral Law from all of them. He served as the High Priest after Ezra.