Many questions remain about the hieroglyphic stair dedicated in a.d. 642 by K'an II, the great king of Caracol. Constituent panels have been found at Caracol, Ucanal, Naranjo, and Xunantunich—archaeological sites spread between Guatemala and Belize. The most recently discovered Panels 3 and 4 at Xunantunich shed light on the tumultuous decades of the seventh century. Panel 4, which opened the hieroglyphic stair, makes a surprising statement from the outset, clarifying that Kanu'l political authority was irrevocably established at Calakmul. This bold statement serves as a synoptic précis for the entire narrative and explains why the deeds of K'an II are related, but only to the extent that these could be interwoven with the history of the Kanu'l. This makes the hieroglyphic stair such an important source, because it tracks the rulers of the Kanu'l dynasty from the vantage of a close ally. These monuments attest to the fissioning of the Kanu'l dynasty and its eventual restoration at Calakmul, from whence Classic Maya politics would be overseen for the remainder of the seventh century. In this article, we build on earlier studies and add our most recent observations and new readings based on renewed inspections of the existing panels.