The Oniad sanctuary at Leontopolis in Egypt was founded by priestly descendants associated with Onias, after priestly conflict and Hellenistic political pressure in Jerusalem. It functioned as a Yahwistic temple center outside Jerusalem, probably serving an Egyptian Israelite population connected to military and settlement networks in the Nile Delta.

Leontopolis is important because it shows an institutional Second Temple offshoot, not merely a diaspora settlement. Its existence raised questions about sacrifice, priestly legitimacy, and Jerusalem’s centrality. The sanctuary continued into the Roman period and was eventually closed after the revolt era. On the map it remains a Second Temple institutional branch rather than a direct ancestor of a later community stream.