Yishmael ben Netanyah ישמעאל בן נתניה

This is not Yishmael, the son of Abraham. The name is one, the men are two, and fifteen centuries lie between them: that one was the son of Abraham and Hagar, this one the son of Netanyah ben Elishama, of the royal line of the house of David, who lived in the days of the destruction of the First Temple.

He fled to Baalis, king of Ammon, who sent him to kill Gedalyah. Yochanan ben Kareach learned of the plan and warned the governor, but Gedalyah did not believe the report.

In the seventh month Yishmael came to Mitzpah with ten men. They ate bread together—and he rose and killed Gedalyah, and with him all the Judeans who were there and the Babylonian soldiers. The next day eighty men came towards Mitzpah from Shechem, Shiloh and Samaria, their beards shaven and their garments torn, bringing offerings to the House of the Lord; Yishmael went out to meet them weeping, brought them into the town and killed seventy of the eighty, casting the bodies into the pit that King Asa had dug. Ten he left alive—they bought their lives with hidden stores of wheat and honey.

The remnant of Mitzpah he led away captive towards the Ammonites. Yochanan ben Kareach and his men overtook him by the great waters at Givon; the captives turned back to Yochanan, while Yishmael escaped with eight men to the Ammonites, and nothing more is said of him.