Complex sentence: He was preceded as ruler of Palenque by his mother, Lady Sak K'uk'; as the Palenque dynasty seems to have had Queens only when there was no eligible male heir, Sak K'uk' transferred rulership to her son upon his official maturity.
Split into simpler sentences: He was preceded as ruler of Palenque by his mother, Lady Sak K'uk'. As the Palenque dynasty seems to have had Queens only when there was no eligible male heir, Sak K'uk' transferred rulership to her son upon his official maturity.