Sophiee1 wrote in post #7 (addressed to N'tanel):
King David is a perfect example. His G-g-g-g-grandmother was Ruth, a convert.

It is recorded in Divrei ha-Yamim Alef 2:12-15 and also in Rut 4:21-22 that

David's father was יִשַׁי Yishai (also spelt אִישַׁי Ishai);
his grandfather was עוֹבֵד Oved;
his great-grandfather was בֹּעַז Bo'az (called אִבְצָן Ivtzan in Shoftim 12:8-10)
and so רוּת Rut, who was married to Bo'az-Ivtzan, was his great-grandmother and not his great-great-great-great-grandmother.

http://mordochai.tripod.com - פרופ' מָרְדֳּכַי בֶּן-צִיּוֹן, יְרוּשָׁלַיִם, אֶרֶץ יִשְׂרָאֵל