Complex sentence: Hoelun was the mother of Mongol Khan Genghis Khan (grandmother of Ogedei Khan, first emperor of Yuan Dynasty) and wife of Yesükhei, the chief of the Kiyad clan.
Split into simpler sentences: Hoelun was the mother of Mongol Khan Genghis Khan and the grandmother of Ogedei Khan, first emperor of Yuan Dynasty. She was the wife of Yesükhei, the chief of the Kiyad clan.