 At the time of his rule, Copán was undergoing an unprecedented rise in population, with residential land use spreading to all available land in the entire Copán Valley.The two surviving stelae of K'ak' Chan Yopaat contain long, hard-to-decipher hieroglyphic texts and are the oldest monuments at the site to survive without being either broken or buried.He reigned for 49 years until his death on 5 February 628.