II Kings 11:1 Halakhah

וַֽעֲתַלְיָה֙ אֵ֣ם אֲחַזְיָ֔הוּ וראתה [רָאֲתָ֖ה] כִּ֣י מֵ֣ת בְּנָ֑הּ וַתָּ֙קָם֙ וַתְּאַבֵּ֔ד אֵ֖ת כָּל־זֶ֥רַע הַמַּמְלָכָֽה׃

Now when Athaliah the mother of Ahaziah saw that her son was dead, she arose and destroyed all the seed royal.

Read halakhic rulings (Jewish law) on II Kings 11:1: and classical halakhic sources.