Hizkiya Gaon Nasi al-Yerushalayim (Qaraite in later life)

Hizkiya's line fled to Northern Mesopotamia and remained in Mosul (present-day Iraq) until the Mongol invasion of 1270CE at which time it was extinguished. It is possible some escaped into the Khazars in the north

Source: “The Scribe - JOURNAL OF BABYLONIAN JEWRY PUBLISHED BY THE EXILARCH’S FOUNDATION ISSN 14 74 – 0230 ISSUE 74 - AUTUMN 2001” pg 59 - The Exilarch’s Tree of the middle ages appears in the Babylonian Haggadahpublished by the Exilarch’s Foundation

The son of Abū Saʿd, Ḥasan (Japheth), married the daughter of the Karaite nasi Hezekiah of Jerusalem sometime between 1040 and 1047. The Karaite linguist Abū l-Faraj Hārūn ibn al-Faraj of Jerusalem witnessed the proxy appointment drawn up in Fustat. After his marriage and his father’s assassination, Ḥasan took up some of his father’s responsibilities at court, and by 1064 he had converted to Islam to become superintendent of the fisc (Ar. ṣāhib bayt al-māl).

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