|Until quite recently this Palenque king was unknown, and even now we have only very sketchy details of his life and reign. The Mexican epigrapher Guillermo Bernal Romero (1999) and Simon Martin were the first to propose the identification of the new king. The only reference we have to his rule is dated AD 742, when U Pakal K'inich Janab' Pakal II oversaw the accession to noble office of a subordinate lord. The only other dated references to U Pakal K'inich Janab' Pakal II range from AD 709-714, before his accession.|
Therefore, both the accession date of U Pakal K'inich Janab' Pakal II and his death date are not known. His predecessor was K'inich Akul Mo' Nab' III, whose latest known date is AD 736. Therefore the best we can say about K'inich Akul Mo' Nab' III's death and U Pakal K'inich Janab' Pakal II's accession is that they took place between AD 736 and 742. The end of U Pakal K'inich Janab' Pakal II's reign is even less certain. Certainly it was before AD 764, when the king K'inich K'uk' B'alam II took office. However it appears that there was an intervening king between the reigns of U Pakal K'inich Janab' Pakal II and K'inich K'uk' B'alam II: that of K'inich Kan B'alam III. The only known date for this little-known ruler is AD 751, so presumably U Pakal K'inich Janab' Pakal II died before AD 751, which would mean that his reign was at most 15 years. Strictly speaking, this ruler should probably just be named K’inich Janab’ Pakal III, but since references to him almost invariably begin with U Pakal K’inich, I list him with the more complete version of his name.
We know that K'inich K'uk' B'alam II was a son of K'inich Akul Mo' Nab' III. Therefore U Pakal K'inich Janab' Pakal II was almost certainly either a younger brother of K'inich Akul Mo' Nab' III or his son (and older brother of K'inich K'uk' B'alam II). Most scholars favour the first alternative, but I think the second is more likely, since we would then have the royal succession passing from K'inich Akul Mo' Nab' III to each of his sons in turn, rather than to a younger brother (U Pakal K'inich Janab' Pakal II) and then back to his sons (K'inich Kan B'alam III and K'inich K'uk' B'alam II), both of whom were almost certainly adults at the time of their father's death.
Three portraits of U Pakal K'inich Janab' Pakal II survive. One is from a broken limestone tablet, several fragments of which were found at the northern end of the Palace. The second portrait was modelled in stucco on a pier inside Temple XIX, and probably represents U Pakal K'inich Janab' Pakal II as a young man before his accession. The accompanying text names U Pakal K'inich Janab' Pakal II not with his full royal name, but rather with his child name. The third portrait occurs on the newly found bench of Temple XXI, where he is shown seated next to K'inich Janab' Pakal I (who was dead at the time of this allegorical scene).